RR ID
One Step Further Question: What is the most common complication of meningococcemia?
Answer: Myocarditis with congestive heart failure or conduction abnormalities
One Step Further Question: What are 3 rare complications of hand-foot-and-mouth disease?
Answer: Myocarditis, pneumonia, meningoencephalitis.
One Step Further Question: What is the treatment for Chagas disease?
Answer: Nifurtimox or benznidazole.
One Step Further Question: Does tetanus immune globulin provide active or passive immunity against the toxins produced by Clostridium tetani?
Answer: Passive.
One Step Further Question: What is the most common source of infection in the septic patient?
Answer: Respiratory system.
One Step Further Question: Which schistosoma species primarily presents with urinary symptoms?
Answer: Schistosoma haematobium.
One Step Further Question: What is the most common Shigella species in developing countries?
Answer: Shigella flexneri.
One Step Further Question: What type of cough is classic of Chlamydia trachomatis pneumonia?
Answer: Staccato cough
One Step Further Question: What is the recommended treatment for Tularemia?
Answer: Streptomycin.
One Step Further Question: Why is direct microscopy inadequate for the identification of Treponema pallidum?
Answer: T. pallidum is too slender, at 0.15 microns in width, to be visualized.
One Step Further Question: What is a Jarisch-Herxheimer reaction?
Answer: The onset of fever, myalgias, headache, tachycardia, and tachypnea after initiation of antibacterial treatment of a spirochete illness.
One Step Further Question: What findings are typically seen on CSF analysis in tuberculous meningitis?
Answer: Very low glucose, elevated protein and a slightly elevated opening pressure.
Rapid Review Ascariasis:
Ascariasis: Patient with a history of travel Complaining of cough, wheezing, abdominal pain, and diarrhea Diagnosis is made by stool studies Most commonly caused by Ascaris lumbricoides round worm Treatment is albendazole
Rapid Review Chlamydial Conjunctivitis
Chlamydial Conjunctivitis Patient will be a neonate 5-14 days after delivery PE will show mucopurulent ocular discharge, eyelid swelling, and erythematous conjunctiva Diagnosis is made by culture Most commonly caused by Chlamydia trachomatis Treatment is oral erythromycin
Rapid Review Cholera
Cholera Patient with a history of drinking contaminated water Complaining of severe, watery diarrhea flecked with mucus "rice water" PE will show dehydration Diagnosis is made by stool culture or darkfield microscopy Most commonly caused by Vibrio cholerae Treatment is supportive. Moderate to severe - fluoroquinolones, macrolides, and tetracyclines
Rapid Review Condyloma Acuminata
Condyloma Acuminata Patient will be complaining of genital lesions PE will show cauliflower-like lesion Most commonly caused by HPV 6 & 11 Comments: most common STD
Rapid Review HIV Infection
HIV Infection Patient will be complaining of abrupt onset of a viral-like illness, fever, malaise, sore throat, headache, arthralgias, anorexia, nausea, vomiting, and rash Diagnosis is made by nucleic acid amplification tests Treatment is HAART
Rapid Review Hand, Foot, Mouth Disease (HFMD)
Hand, Foot, Mouth Disease (HFMD) Patient will be a child younger than 5 years of age Complaining of decreased appetite and fever PE will show an oral exanthem plus a macular, maculopapular, or vesicular rash on the hands and feet Most commonly caused by Coxsackievirus A Treatment is supportive
Rapid Review Herpes Simplex Labialis
Herpes Simplex Labialis Patient will be complaining of painful oral lesions PE will show painful vesicles and erosions on the tongue, buccal mucosa, and lips Labs will show multinucleated giant cells on Tzanck smear Diagnosis is made clinically. Gold standard is tissue culture with polymerase chain reaction (PCR) Most commonly caused by herpes simplex virus (HSV) type 1 Treatment is topical antiviral therapy or oral acyclovir
Rapid Review Malaria
Malaria P. falciparum (deadliest), P. ovale, P. vivax, P. malariae P. ovale, P. vivax: hepatic phase Anopheles mosquito Immigrant, traveler Irregular fevers, diaphoresis P. falciparum: cerebral malaria, Blackwater fever Uncomplicated, no resistance areas rx: chloroquine Complicated, P. falciparum rx: quinidine + doxycycline
Rapid Review Occupational Postexposure Prophylaxis (PEP)
Occupational Postexposure Prophylaxis (PEP) HIV PEP given with mucous membrane exposure or skin compromise Tenofovir + emtricitabine plus raltegravir HBV: Prior vaccination: PEP not needed No prior immunization: HBIG + HBV vaccine HCV: No PEP available
Rapid Review Retropharyngeal Abscess
Retropharyngeal Abscess 3-5 years of age S. aureus, GAS, anaerobes, foreign body Sore throat, dysphagia Toxic appearing, drooling, ↓ neck extension, fever Cri du canard (duck "quack") Neck x-ray: widened retropharyngeal space twice the size of the vertebral body CT Rx: IV ABX, ENT consultation
Rapid Review Sepsis Syndromes
Sepsis Syndromes SIRS: 2 or more of the following T >38° or <36° HR > 90 bpm RR > 20 bpm or PCO2 < 32 mmHg WBC > 12,000 or < 4000 Sepsis: SIRS + infection Severe sepsis: sepsis + organ dysfunction Septic shock: sepsis + refractory hypotension
Rapid Review Sepsis Syndromes
Sepsis Syndromes SIRS: 2 or more of the following T >38° or <36° HR > 90 bpm RR > 20 bpm or PCO2 < 32 mmHg WBC >12000/mm3 or <4000/mm3 Sepsis: SIRS + infection Severe sepsis: sepsis + organ dysfunction Septic shock: sepsis + refractory hypotension
Rapid Review Tetanus
Tetanus Clostridium tetani Toxin mediated Trismus (lockjaw) Generalized tetanus is most common Strychnine can mimic Benzodiazepines, metronidazole (not penicillin), TIG, immunization
One Step Further Question: True or false: Pinworm eggs best survive in warm, dry conditions?
Answer: False, pinworms eggs survive the best in cooler, more humid conditions.
One Step Further Question: What is the most common cardiac manifestation of Lyme disease?
Answer: First degree AV block.
One Step Further Question: How is Brudzinski's sign performed?
Answer: Forceful flexion of the neck results in involuntary flexion of the hips, knees, and ankles.
One Step Further Question: What is the most common cause of septic arthritis in patients under 35 years of age?
Answer: Gonococcal arthritis.
One Step Further Question: What is the most common cause of septic arthritis in patients under 50 years of age?
Answer: Gonococcus arthritis.
One Step Further Question: Parvovirus-induced transient aplastic crisis is most likely to occur in patients with which disorder?
Answer: Hematologic disorders like sickle cell anemia, thalassemia, or spherocytosis.
One Step Further Question: What is the most common cause of foodborne botulism?
Answer: Home canned foods.
One Step Further Question: What disease has a high rate of co-infection with syphilis?
Answer: Human immunodeficiency virus.
One Step Further Question: What is "Blackwater" fever?
Answer: "Blackwater" fever describes the presence of hemoglobinuria resulting from hemolytic anemia in malaria.
One Step Further Question: What pathognomonic hair manifestation can occur in patients with secondary syphilis?
Answer: "Moth-eaten" alopecia.
One Step Further Question: What is the usual timeframe between exposure to HIV and development of clinical symptoms?
Answer: 2-4 weeks.
One Step Further Question: Current guidelines recommend the MMR vaccination at what two ages?
Answer: Between 12-15 months and between 4-6 years.
One Step Further Question: Which disease is transmitted by the reduviid bug?
Answer: Chagas disease.
One Step Further Question: What late skin finding is commonly associated with staphylococcal toxic shock syndrome?
Answer: Desquamation of palms and soles 1-2 weeks after onset of symptoms.
One Step Further Question: What is the most common complication of measles?
Answer: Diarrhea.
One Step Further Question: True or false: In high-risk patients presenting for suspected influenza, antiviral treatment should be delayed until the results of diagnostic testing confirm the illness?
Answer: False.
One Step Further Question: What is the Jarisch-Herxheimer reaction?
Answer: Fever, myalgias, and headache developing after penicillin therapy for syphilis.
One Step Further Question: In infants, erythromycin use is a risk factor for development of what gastrointestinal condition?
Answer: Infantile hypertrophic pyloric stenosis.
One Step Further Question: Which tick is responsible for the spread of Lyme disease?
Answer: Ixodes tick.
One Step Further Question: What is the name of the reaction that may occur during the first 24 hours of syphilis treatment?
Answer: Jarisch-Herxheimer reaction.
One Step Further Question: Does natural infection with diphtheria induce immunity?
Answer: No.
One Step Further Question: Is Salmonella a normal part of the human intestinal flora?
Answer: No.
One Step Further Question: Is single-drug therapy of Mycobacterium tuberculosis and nontuberculous mycobacteria recommended?
Answer: No.
One Step Further Question: Does the Jarisch-Herxheimer reaction occur during the treatment of tertiary syphilis?
Answer: No. It is limited to primary and secondary syphilis.
One Step Further Question: How is Rocky Mountain spotted fever diagnosed?
Answer: PCR can be used initially, and serial serologic examinations by indirect fluorescent antibody confirm the diagnosis, retrospectively.
One Step Further Question: What is Fitz-Hugh-Curtis?
Answer: Peri-hepatitis - a complication of pelvic inflammatory disease.
One Step Further Question: What is the most common complication of herpes zoster?
Answer: Postherpetic neuralgia.
One Step Further Question: Which anti-parasitic agent is used to treat schistosomiasis?
Answer: Praziquantal.
One Step Further Question: What organism is responsible for hot tub folliculitis in most cases?
Answer: Pseudomonas aeruginosa.
One Step Further Question: What is the best marker of immunosuppression in HIV-positive patients?
Answer: The CD4 cell count is the best predictor of susceptibility to opportunistic infection and immunologic dysfunction.
One Step Further Question: Chest radiographs of patients with tuberculosis show opacities most often in which portion of the lungs?
Answer: The apices of the lungs.
One Step Further Question: Why does a healthy adult with uncomplicated Group A strep pharyngitis generally not require antibiotic treatment?
Answer: The occurrence of the initial episode of acute rheumatic fever is unlikely after 15 years of age.
One Step Further Question: The causative organism of Lyme disease, Borrelia burgdorferi, belongs to which class of organisms?
Answer: The organism that causes Lyme disease is a spirochete (a spiral-shaped bacteria) as is the organism that causes syphilis.
One Step Further Question: What is the definition of Sepsis Criteria?
Answer: The presence of SIRS + a suspected or confirmed source of infection.
One Step Further Question: How should a penicillin allergic pregnant patient be treated for syphilis?
Answer: They should be desensitized to and treated with penicillin.
One Step Further Question: What other opportunistic infection can be prevented with TMP-SMX?
Answer: Toxoplasma gondii encephalitis.
One Step Further Question: How long should a deer tick be attached before prophylactic treatment to prevent Lyme disease is recommended?
Answer: Typically, longer than 36 hours.
One Step Further Question: What test may be falsely positive in malaria patients?
Answer: VDRL (Venereal Disease Research Laboratory test)
One Step Further Question: Which vitamin is deficient in children with chronic ascariasis?
Answer: Vitamin A.
One Step Further Question: What stain is used to visualize Bartonella in a biopsy specimen?
Answer: Warthin-Starry stain.
Rapid Review Botulism
Botulism Patient with a history of eating canned food Complaining of symmetric descending paralysis Most commonly caused by Clostridium botulinum Treatment is antitoxin
Rapid Review Cryptococcal Meningitis
Cryptococcal Meningitis HIV, CD4 < 100 Meningismus uncommon Rx: amphotericin B + flucytosine
Rapid Review Erysipelas
Erysipelas S. pyogenes Fever, chills → painful rash Face Bright red color, sharp margins Consider admission in all patients IV ABX
Rapid Review Genital Herpes Simplex
Genital Herpes Simplex Patient will be complaining of a painful genital rash PE will show grouped erythematous, shallow, cluster of vesicles and lymphadenopathy Labs will show multinucleated giant cells on Tzanck smear Diagnosis is made clinically. Gold standard is tissue culture with polymerase chain reaction (PCR) Most commonly caused by herpes simplex virus (HSV) type 2 Treatment is acyclovir
Rapid Review West Nile Virus
West Nile Virus Mosquitos Summer/fall Flulike sx, URI sx, rash Complication: meningoencephalitis
Rapid Review Oral Hairy Leukoplakia
Oral Hairy Leukoplakia EBV Lateral aspect of tongue Lesions do not scrape off (unlike thrush) HIV
One Step Further Question: What symptom is pathognomonic for rabies infection?
Answer: Hydrophobia.
Rapid Review Initial Antiretroviral Regimen for HIV Treatment-Naïve Patients
Initial Antiretroviral Regimen for HIV Treatment-Naïve Patients 2 NRTIs + 1 drug from one of the following classes: NNRTI PI INSTI
Rapid Review Sporotrichosis
Sporotrichosis PE will show red ulcer with lymphcutaneous spread Most commonly caused by rose thorn infection, Sporothrix schenckii Treatment is itraconazole
Rapid Review Erythema Infectiosum (Fifth Disease)
Erythema Infectiosum (Fifth Disease) Patient will be a child With a history of URI symptoms 3 - 4 days prior to rash PE will show "slapped cheek" rash Most commonly caused by parvovirus B19 Comments: Aplastic crisis in sickle cell patients
Erythema Patterns
Erythema marginatum (A) is an evanescent, pink or faintly red, non-pruritic rash involving the trunk and sometimes the limbs that is associated with acute rheumatic fever. Erythema multiforme (C) is an acute, immune-mediated condition characterized by the appearance of distinctive target-like lesions on the skin. These lesions are often accompanied by erosions or bullae involving the oral, genital or ocular mucosae. It is most commonly induced by infection. Erythema nodosum (D) is characterized by red or violet subcutaneous nodules that usually develop in a pretibial location and is presumed to represent a delayed hypersensitivity reaction caused by various infectious agents, drugs, and other diseases. Erythema migrans is the primary manifestation of early Lyme disease.
Rapid Review Mumps
Mumps Viral paramyxovirus Winter/spring Parotitis Orchitis Deafness Aseptic meningitis
Rapid Review Pneumocystis Pneumonia (PCP)
Pneumocystis Pneumonia (PCP) Patient with a history of HIV Complaining of gradual onset of non-productive cough Labs will show CD4 < 200, increased LDH CXR will show bilateral infiltrates (bat wing pattern) Most commonly caused by Pneumocystis jirovecii Treatment is TMP-SMX
Rapid Review Pregnancy: Contraindicated Vaccines
Pregnancy: Contraindicated Vaccines Mumps-Measles-Rubella Varicella (chicken pox) Yellow fever BCG Vaccinia
Rapid Review Primary Syphilis
Primary Syphilis Patient will have been sexually active 2 - 3 weeks ago Complaining of bump on his penis PE will show painless, "Punched out" lesion Diagnosis is made by darkfield microscopy Most commonly caused by Treponema pallidum Treatment is single IM injection of benzathine penicillin Comments: syphiLIS is painLESS ulcer
An eight-year-old girl is seen in your office after recently moving from Central America. She has been complaining of abdominal pain and not been eating well. She appears malnourished and has mild diffuse tenderness to palpation on physical exam. The rest of the physical exam is normal. You order a complete blood count and find the hemoglobin level at 8.5 g/dl. Which of the following infections is this child most likely to have? Ascariasis Hookworm disease Neurocysticercosis Pinworm infection
orrect Answer ( B ) Explanation: Hookworm larvae penetrate the skin, causing a local erythematous, papular rash and pruritus at the site of entry. The larvae spread hematogenously to the lungs, to the bronchial tree, to the pharynx and are subsequently swallowed. They reside in the small intestine, specifically the duodenum and jejunum, and feed on host blood. Patients with poor nutrition and decreased iron reserve are at risk of developing an iron deficiency anemia. Severe infections can lead hypoproteinemia resulting in anasarca. Hookworm disease is treated with one oral dose of albendazole 400 mg or mebendazole 100 mg for three days.
A 16-year-old girl is seen in the emergency room after a new, generalized tonic-clonic seizure. She has no history of seizures and recently moved from the Caribbean with her family. An MRI of the head shows multiple calcified cysts in the parieto-occipital region. Which of the following is the most likely infection in this child? Ascariasis Hookworm disease Neurocysticercosis Strongyloidiasis
orrect Answer ( C ) Explanation: Taenia solium, the pork tapeworm, is transmitted to humans by ingestion of food or water contaminated with the eggs. In the small intestine, the egg releases an oncosphere that crosses the gut wall and spreads hematogenously to the brain leading to neurocysticercosis. Consumption of undercooked pork produces an intestinal infection that is caused by the adult worm. Individuals infected with an adult worm can infect themselves or others with the eggs via fecal-oral route. Neurocysticercosis should be suspected in any child with new onset seizures and a history of living in an endemic area or exposed to someone from an endemic area. MRI of the head is the most useful test given that it provides information about cyst viability and associated inflammation. Albendazole is the pharmacologic drug choice however; antiparasitic agents are generally not used as most cysts resolve spontaneously over time.
One Step Further Question: What does the fourth generation combination HIV-1/2 immunoassay detect?
Answer: HIV-1 antibodies, HIV-2 antibodies and HIV-1 p24 antigen.
One Step Further Question: What is the risk of anaphylactic reaction to cephalosporins in a penicillin allergic patient?
Answer: < 10%.
One Step Further Question: What is the most important predictor of mortality in a patient with necrotizing fasciitis?
Answer: A history of diabetes.
One Step Further Question: What is the mechanism responsible for the lymphocytosis seen in children with pertussis?
Answer: A major exotoxin and virulence factor produced by Gram-negative B. pertussis organisms is known as lymphocytosis-promoting factor.
One Step Further Question: What is the treatment for erysipelas?
Answer: A parenteral antistreptococcal antibiotic such as ceftriaxone or cefazolin.
One Step Further Question: What is the most common neurological symptom from second-stage Lyme disease?
Answer: A unilateral or bilateral facial nerve palsy.
One Step Further Question: What is the leading cause of mortality in sickle cell patients?
Answer: Acute Chest Syndrome (ACS).
One Step Further Question: In which trimester is mumps most devastating?
Answer: Congenital infection is rare, but there is increased likelihood of fetal loss if it occurs in the 1st trimester.
One Step Further Question: What are the alternative agents for prophylactic treatment of PCP in patients who cannot take TMP-SMX?
Answer: Dapsone, atovaquone suspension, and aerosolized pentamidine.
One Step Further Question: How long after female pinworms lay their eggs do they become infectious?
Answer: 4-6 hours.
One Step Further Question: What type of tick is the most common vector of Rocky Mountain spotted fever in the eastern and south central United States?
Answer: American dog tick.
One Step Further Question: What class of antibiotics is contraindicated for use in the treatment of botulism?
Answer: Aminoglycosides.
One Step Further Question: What is the treatment for the opportunistic infection, Cryptococcus?
Answer: Amphotericin B combined with flucytosine.
One Step Further Question: What antibiotics are associated with the development of a morbilliform rash in a patient with infectious mononucleosis?
Answer: Ampicillin and amoxicillin.
One Step Further Question: What is the name for the inflammatory reaction to Candida that results in soreness and fissuring at the corners of the mouth?
Answer: Angular cheilitis.
One Step Further Question: How long is the incubation period for malaria infection?
Answer: Approximately 12-14 days.
One Step Further Question: What is the most common manifestation of late Lyme disease?
Answer: Arthritis.
One Step Further Question: Name 3 substances that contain salicylates?
Answer: Aspirin, Pepto-Bismol, oil of wintergreen (methyl salicylate)
One Step Further Question: What is the typical distribution of weakness caused by West Nile meningoencephalitis?
Answer: Asymmetric; isolated facial involvement may also be seen.
One Step Further Question: What is the treatment for Chlamydia?
Answer: Azithromycin 1 gram x 1 or doxycycline 100 mg 1 tablet twice daily for 1 week.
One Step Further Question: Which bacterium is responsible for whooping cough?
Answer: Bordetella pertussis.
One Step Further Question: What is the deep-tendon response in patients with botulinum poisoning?
Answer: Botulinum toxin prevents the release of acetylcholine from motor neurons resulting in flaccid paralysis and diminished deep-tendon reflexes.
One Step Further Question: The human herpesvirus 6 predominantly infects which type of cell?
Answer: CD4 lymphocytes.
One Step Further Question: What type of cell does HIV infect?
Answer: CD4+ T lymphocytes.
One Step Further Question: What are the most common fungal causes of purulent pericarditis?
Answer: Candida and histoplasma species.
One Step Further Question: What other antibiotic can be used to treat Lyme disease in a pregnant patient?
Answer: Cefuroxime axetil, a second-generation oral cephalopsporin.
One Step Further Question: What is the cause of lymphogranuloma venereum?
Answer: Chlamydia trachomatis serovars L1-L3.
One Step Further Question: Which deficiency of the non-specific limb of the immune system has been clearly associated with meningococcal sepsis and meningitis?
Answer: Complement deficiency C5-C9, properdin, factor H, or factor D has been associated with a special susceptibility to infections caused by N. meningitides.
One Step Further Question: Due to increased antibiotic resistance, what is the current recommended treatment for gonorrhea?
Answer: Dual therapy with ceftriaxone and either azithromycin or doxycycline.
One Step Further Question: Which non-nucleoside reverse transcriptase inhibitor has an association with suicidal ideation?
Answer: Efavirenz.
One Step Further Question: For which tick-borne illness is doxycycline the recommended treatment regardless of age?
Answer: Ehrlichiosis.
One Step Further Question: Infectious mononucleosis is causes by which virus?
Answer: Epstein Barr Virus (EBV).
One Step Further Question: What botulism antitoxin is used to treat botulism?
Answer: Equine serum heptavalent botulism antitoxin.
One Step Further Question: What is the name of the rash associated with Lyme disease?
Answer: Erythema migrans—described as a circular lesion with central clearing or erythema at the site of a tick bite.
One Step Further Question: What confirmatory test should be done next if a patient has a positive RPR?
Answer: FTA-ABS test (detects antibodies to the bacteria Treponema pallidum)
One Step Further Question: What are the four types of clinical tetanus?
Answer: Generalized, localized, cephalic and neonatal.
One Step Further Question: Should you order serologic testing to diagnose toxoplasmosis?
Answer: Generally, no, because antibodies are fairly prevalent in the general population.
One Step Further Question: What is the most common cause of adult epiglottitis?
Answer: H. influenzae type B is the most commonly identified bacterial pathogen and is associated with severe disease. However, very few patients actually have the etiologic organism identified.
One Step Further Question: What type of tissue is Clostridium tetani unable to grow in?
Answer: Healthy tissue.
One Step Further Question: What is the most infectious blood born pathogen?
Answer: Hepatitis B (followed by Hepatitis C, then HIV).
One Step Further Question: What infection is the most common precipitator of erythema multiforme?
Answer: Herpes simplex virus.
One Step Further Question: What electrolyte abnormality can be seen in advanced cases of RMSF?
Answer: Hyponatremia.
One Step Further Question: How is babesiosis identified on a peripheral smear?
Answer: Identification of intracellular organism in erythrocytes.
One Step Further Question: Ascariasis is commonly found is which part of the gastrointestinal tract?
Answer: Ileum.
One Step Further Question: What is the major means of prevention of influenza infection?
Answer: Immunization.
One Step Further Question: What class of bacteria is Bartonella henselae?
Answer: Intracellular gram-negative rod.
One Step Further Question: What would the peripheral smear show in a patient with ehrlichiosis?
Answer: Intracellular morulae.
One Step Further Question: What is the most common vector-borne infection in the United States and Europe?
Answer: Lyme disease.
One Step Further Question: What is the treatment for pertussis?
Answer: Macrolide antibiotics (e.g., erythromycin, clarithromycin, azithromycin). Prevention is achieved through administration of the pertussis vaccine DTaP in children < 7 years old, Tdap in children > 7 years and adults.
One Step Further Question: What is the treatment for Mycobacterium avium complex?
Answer: Macrolide-based (clarithromycin and azithromycin) multidrug regimen.
One Step Further Question: What are the classic viral exanthems?
Answer: Measles (first disease), rubella (third disease), erythema infectiosum (fifth disease), and roseola infantum (sixth disease).
One Step Further Question: What is the treatment for oral hairy leukoplakia?
Answer: Most cases are self-limited, but antiviral agents like acyclovir, ganciclovir and foscarnet can be considered.
One Step Further Question: What finding on a Tzank smear confirms the diagnosis of an HSV infection?
Answer: Multinucleated giant cells.
One Step Further Question: How significant is the threat to male fertility resulting from testicular involvement as part of mumps virus disease?
Answer: Mumps orchitis rarely leads to sterility, but it may contribute to subfertility. It can also lead to defects in sperm numbers and movement.
One Step Further Question: What is the most important independent predictor of mortality for patients with spontaneous bacterial peritonitis?
Answer: Renal dysfunction.
One Step Further Question: What is considered the gold standard in diagnosing influenza infection?
Answer: Reverse transcription-polymerase chain reaction or viral culture of nasopharyngeal or throat secretions
One Step Further Question: What medication regimen is recommended for post-exposure prophylaxis (PEP) following an exposure to HIV?
Answer: Triple antiretroviral therapy, such as tenofovir and emtricitabine, plus either raltegravir OR dolutegravir.
One Step Further Question: True or false: H. capsulatum can remain dormant for a number of years after initial exposure with reactivation occurring much later?
Answer: True.
One Step Further Question: True or false: chloroquine is safe during pregnancy?
Answer: True.
One Step Further Question: True or false: the majority of herpes simplex infections are asymptomatic?
Answer: True.
One Step Further Question: How long does it typically take an immunocompetent patient to clear a human papillomavirus infection?
Answer: Two years.
One Step Further Question: How common is hearing loss in Ramsay Hunt syndrome?
Answer: Up to 50% of people experience ipsilateral hearing loss.
Rapid Review Reye's Syndrome
Reye's Syndrome Child with viral illness treated with aspirin Fatty liver Encephalopathy → delirium, seizures Vomiting Hypoglycemia Avoid aspirin in children (except in Kawasaki disease
Tick Borne Dz Review
Babesiosis (A) is a malaria-like illness caused by Babesia microti protozoan. It is transmitted by Ixodes ticks in the northeastern United States; it also has been acquired by transfusion. Like malaria, the protozoan infects red blood cells, causing fever, drenching sweats, myalgias, and headache. It is occasionally associated with a rash. Colorado tick fever (B) is caused by the Coltivirus and transmitted by the dog tick (similar to RMSF) in the western United States. Patients present 3-6 days after a bite with sudden fever, headache, myalgias, and photophobia. A transient petechial rash may occur. In 50% of cases, symptoms resolve and then recur after 3 days. Lyme disease (C) is transmitted by the bite of an Ixodes scapularis tick and is the most common vectorborne disease in the United States. Early infection is associated with the classic erythema migrans rash, a circular lesion with central clearing or erythema at the site of a tick bite.
Rapid Review Bell's Palsy
Bell's Palsy Patient often with a history of viral prodrome Complaining of waking up with unilateral facial nerve paralysis, hyperacusis and taste disturbance PE will show CN VII nerve palsy that does not spare the forehead Most commonly caused by HSV Treatment is prednisone, artificial tears, tape eyelid shut Comments: Bilateral: Lyme disease, infectious mononucleosis
Rapid Review Bell's Palsy
Bell's Palsy Patient with a history of viral prodrome Complaining of waking up with unilateral facial nerve paralysis, hyperacusis and taste disturbance PE will show CN VII nerve palsy that does not spare the forehead Most commonly caused by HSV Treatment is prednisone, artificial tears, tape eyelid shut Comments: Bilateral: Lyme disease, infectious mononucleosis
Rapid Review Botulism
Botulism Patient will be an infant With a history of eating honey Complaining of feeble cry, constipation PE will show symmetric descending paralysis ("floppy baby") Most commonly caused by Clostridium botulinum Treatment is IV botulism Ig
Rapid Review Bronchiolitis
Bronchiolitis Patient will be an infant Complaining of difficulty breathing PE will show respiratory distress, polyphonic wheezing, and rales CXR will show diffuse infiltrates Diagnosis is made by history and physical exam Most commonly caused by respiratory syncytial virus (RSV) Treatment is supportive care
Rapid Review Chlamydia Cervicitis
Chlamydia Cervicitis Diagnosis is made by nucleic acid amplification testing (NAAT) Most commonly caused by Chlamydia trachomatis Treatment is azithromycin Comments: Most commonly reported sexually transmitted disease in the United States Empirically treat for concomitant gonorrhea The United States Preventive Services Task Force recommends routine screening for sexually active women < 24 years of age, and in women > 24 years of age who are at increased risk
Rapid Review Cat Scratch Disease
Cat Scratch Disease Patient with a history of scratch by a kitten or cat Complaining of subacute, regional lymphadenitis PE will show a vesicle, which became an erythematous papule Most commonly caused by Bartonella henselae Treatment is mainly supportive, azithromycin if needed
Rapid Review Chancroid
Chancroid Patient will be sexually active Complaining of painful genital ulcers PE will show pustules which ulcerate, ulcers on an erythematous base covered by a gray or yellow purulent exudate and painful lymphadenopathy (bubo) Most commonly caused by Haemophilus ducreyi Treatment is ceftriaxone 250 mg or one gram of oral azithromycin
A 8-year-old boy presents with a 2-day history of severe, watery diarrhea. He is currently living in a Haitian refugee camp. On exam, the child is afebrile, but appears dehydrated. He is actively passing large amount of watery diarrhea that is flecked with mucous. Darkfield microscopy of the stool reveals mobile organisms. Which of the following is the most likely diagnosis? Cholera Rotavirus Salmonellosis Shigellosis
Correct Answer ( A ) Explanation: This boy most likely has cholera. Cholera is an infectious diarrheal illness caused by a toxin producing strain of Vibrio cholerae. Cholera is most commonly seen in resource-limited settings with poor access to clean water sources. Cholera is endemic approximately 50 countries, many of which are in Asia, Africa, and South America. V. cholerae is a gram-negative curved rod that is highly motile and halophilic. Cholera is transmitted through ingestion of contaminated food or water. Incubation period varies based on size of inoculum and host immune status. Average incubation period is 1-2 days, although it can range from a few hours to 5 days. Diarrhea is the hallmark symptom. Other common symptoms include abdominal discomfort, borborygmi, and vomiting. Fever and tenesmus are uncommon findings. The diarrhea associated with cholera is classically described as "rice-water" stool and typically has a fishy odor. Signs of severe dehydration may develop within hours of diarrhea onset. Signs of severe hypovolemia include sunken eyes, dry mucous membranes, cold skin, decreased skin turgor, apathy, and lethargy. The most common laboratory abnormality is isonatremic dehydration. Diagnosis is based on clinical manifestations, but can be confirmed with stool culture or darkfield microscopy. Aggressive fluid repletion is the main treatment of cholera. Mild to moderate cases can be treated with oral rehydration solution. Severe cases may require intravenous fluids. Antibiotics are recommended in moderate to severe cases. Choices of antibiotics include fluoroquinolones, macrolides, and tetracyclines. A cholera vaccine is available for endemic areas and in areas at risk for an outbreak.
A 23-year-old man presents to your clinic with complaints of fever, sore throat, headache and a rash on his chest. While taking his history, the patient denies any new sexual partners but appears uncomfortable answering the question. Physical exam reveals a temperature of 102°F, non-tender cervical and axillary lymphadenopathy, pharyngeal edema without exudate, and a maculopapular rash on the chest and neck. Which of the following is the most likely diagnosis? HIV Mononucleosis Pityriasis rosea Systemic lupus erythematosus
Correct Answer ( A ) Explanation: Acute HIV infection can present with a number of non-specific symptoms that resemble other illnesses. Medical providers need a high degree of clinical suspicion to make the diagnosis. Patients may be reluctant to answer questions honestly about their sexual behavior or drug use or may not perceive their behavior as being high risk and therefore omit important information in the history. This can impede making a correct diagnosis. Patients presenting with fever, rash, pharyngitis, lymphadenopathy and myalgias should have acute HIV infection included in the differential diagnosis. Mononucleosis (B) caused by Epstein-Barr virus presents with similar clinical features to acute HIV infection. Abrupt onset of symptoms, presence of rash and diarrhea, and lack of tonsillar exudates are clinical features seen in acute HIV infection but not in mononucleosis.
Which of the following tests is recommended for routine HIV screening? Fourth generation combination HIV-1/2 immunoassay HIV-1 Immunofluorescence assay HIV-1 Western blot HIV-1/HIV-2 antibody differentiation immunoassay
Correct Answer ( A ) Explanation: Approximately 16% of individuals in the United States infected with HIV are not aware of their HIV status. Routine screening for HIV is now recommended for all individuals aged 15 to 65 years old. New recommendations from the Centers for Disease Control are to use a fourth generation combination HIV-1/2 immunoassay as the initial screening test. Use of this test allows for detection of HIV sooner after infection with the virus than with previous tests. Previous recommendations for a laboratory diagnosis of HIV infection were to use the HIV-1 Immunofluorescence assay (B) and HIV-1 Western blot (C) tests. The fourth generation combination HIV-1/2 immunoassay has replaced these tests due to being more accurate, having a faster turnaround time and fewer indeterminate results. A positive result with this test requires confirmation of HIV infection with the HIV1/HIV2 antibody differentiation immunoassay (D).
A seven-year-old boy is seen in your clinic with cough, wheezing, abdominal pain, and diarrhea. He recently returned from a family vacation to India. You get stool studies that yield a diagnosis of ascariasis. Which of the following is the best medication for this child? Albendazole Ivermectin Metronidazole Pyrantel pamoate
Correct Answer ( A ) Explanation: Ascariasis (Ascaris lumbricoides round worm) infection is a result of ingestion of infective eggs. Initially, children may present with cough, dyspnea, wheezing, and hemopytsis as a result of larvae travel via systemic circulation to the lungs. After lung invasion, the larvae travel down small intestines by passing over the epiglottis and are subsequently swallowed. This can lead to abdominal pain, distension, small bowel obstruction, peritonitis, and malabsorption. Stool eggs can be detected approximately six to eight weeks after ingestion and often symptoms do not present till weeks after ingestion. The treatment of choice is a one-time oral dose of albendazole 400 mg. This medication is metabolized after absorption and distributes systemically, making it very effective
A 5-year-old girl presents to the emergency department with a 2-day history of grossly bloody diarrhea, abdominal cramping, and fever. Other children from her daycare have similar symptoms. On physical exam, the child appears mildly dehydrated and has mild lower abdominal tenderness to palpation. A stool study reveals fecal leukocytes and stool culture grows nonmotile, facultatively anaerobic, gram-negative rods. After initial fluid resuscitation, which of the following is the most appropriate treatment? Azithromycin Ceftriaxone Ciprofloxacin Loperamide
Correct Answer ( A ) Explanation: Azithromycin is the most appropriate treatment for shigellosis in patients < 18 years of age. Shigellosis is a type of bacterial diarrhea. In the United States, most cases of shigellosis are caused by Shigella sonnei. Most cases in the United States are seen in daycare centers and in crowded living conditions. The majority of cases are transmitted through fecal-oral spread. Other modes of transmission include food-borne and sexual transmission. Shigella sp. have a relatively low infectious dose due to their ability to survive passage through the stomach's acidic environment. Upon reaching the colon, they invades the mucosal cells and induces an intense inflammatory response, which leads to death of epithelial and immune cells and creates colonic ulcerations and abscesses. The average incubation period is 3 days. Presenting symptoms may include abdominal pain, fever, mucoid or bloody diarrhea, and tenesmus. Stool frequency is usually 8-10 per day and significant fluid loss is not common. Diagnosis is based on small, volume bloody diarrhea, abdominal cramps, fever and with stool studies. Direct microscopy often reveals fecal leukocytes and red blood cells. Culture reveals non-motile, facultatively anaerobic, gram-negative rods that do not ferment lactose. Treatment should begin with oral or intravenous rehydration. For children with underlying immunodeficiency or who have toxemia or bacteremia, intravenous ceftriaxone is recommended. Azithromycin is the first-line oral treatment in children. Fluoroquinolone antibiotics are first-line treatment in adults. Complications of shigellosis include rectal prolapse, intestinal obstruction, colonic perforation, bacteremia, electrolyte imbalances, leukemoid reactions, and hemolytic-uremic syndrome.
19-year-old man presents with headache and a peripheral cranial nerve seven palsy. He states that he was recently hiking in Connecticut and had numerous tick bites. What CSF finding is most sensitive for Lyme meningitis? Borrelia burgdorferi antibody Decreased glucose level Decreased protein level Positive PCR assay
Correct Answer ( A ) Explanation: B. burgdorferi antibody is the most sensitive test for Lyme meningitis and will be present in 80-90% of patients. Lyme disease is the most common tick borne illness in the US. The disease is caused by Borrelia burgdorferi, a spirochete. After a bite from the Ixodes scapularis tick and transmission of the spirochete, patients typically develop a non-specific viral illness accompanied by the erythema migrans rash. The rash appears at the site of the tick bite and spreads outwards eventually with central clearing. Early disease can progress to the acute disseminated form where hematogenous spread can cause multiorgan involvement. Neurologic signs develop about four weeks after the initial infection. The most common presentation of neurologic involvement is a fluctuating meningoencephalitis with accompanying cranial and peripheral neuropathies. The most common cranial neuropathy is a seventh nerve palsy. CSF samples should be obtained and sent for B. burgdorferi antibodies (IgG or IgA) since this is the most sensitive test.
A two-month-old male infant presents in August with a copious, bubbly, tenacious mucous discharge from his nose and mouth. He also has a repetitive paroxysmal cough terminated by an inspiratory "whoop" and followed by a tussive episode. The infant had upper respiratory symptoms for the past two weeks. His parents report a possible seizure before taking him to the emergency room. Other infants in his day care center have been diagnosed with respiratory infections associated with a "prolonged" cough. The infant is pale and cyanotic, tachypnic and bradycardiac as well as anxious looking. Physical examination of his chest is consistent with a lobar pneumonia. What is the diagnostic method of choice in this patient? Bordetella pertussis-specific polymerase chain reaction (PCR) Bordetella pertussis-specific serology Culture for Bordetella pertussis Lymphocyte count
Correct Answer ( A ) Explanation: B. pertussis PCR performed on a properly obtained nasopharyngeal specimen processed by an experienced lab is currently the method of choice. Although some false positive PCR results have been reported, it is much more sensitive than the difficult to obtain bacterial culture of this fastidious organism. Results can also be obtained fairly rapidly.
A 23-year-old woman presents with a complaint of weakness that started in her bilateral arms and moved down to her bilateral legs. She ate at a friend's house who cans her own food. A few hours later, she complained of abdominal pain and vomiting before endorsing upper extremity weakness. Which of the following is the most likely diagnosis? Botulism Chronic inflammatory demyelinating polyneuropathy Guillain Barre syndrome Salmonellosis
Correct Answer ( A ) Explanation: Botulism is a life-threatening disease caused by Clostridium botulinum, a gram-positive anaerobic bacterium that exists in soil and marine sediment. The spores of the bacterium are heat-resistant, but in restricted oxygen environments, low acidity water, or ideal temperatures, the spores will grow into toxin-producing bacilli. The Clostridium botulinum toxin enters the body through wounds or ingestion of certain foods, such as home-canned goods or raw honey. In foodborne botulism, the onset of symptoms is usually between 12 to 36 hours after ingestion and typically begins with nausea, vomiting, abdominal pain, and diarrhea. These symptoms are then followed by neuropathic symptoms of symmetric descending weakness throughout the body. The patient typically remains responsive and sensation is preserved. Diagnosis is made by testing the blood for the toxin and treatment includes respiratory airway protection, supportive care, and administration of the botulism antitoxin. Patients typically die from respiratory failure.
A 26-year-old man presents with a severe retro-orbital headache, a sudden-onset fever of 103.3°F, nausea, and severe myalgias six days after returning from Panama. On exam, he has a morbiliform rash on his abdomen and back. Which of the following is most likely responsible for his symptoms? Dengue fever Japanese encephalitis Malaria Yellow fever
Correct Answer ( A ) Explanation: Dengue fever is the second most important tropical, febrile illness after malaria. Dengue has a short incubation period of four to seven days. It is transmitted by the Aedes aegypti mosquito. Travelers returning from Africa, the Americas and the Indian subcontinent tend to have classic dengue. Those returning from Southeast Asia usually have the hemorrhagic variant. Classic dengue manifests as sudden onset of high fever, with retro-orbital headache, nausea, vomiting, severe myalgias, and a rash. It is also known as "breakbone fever" due to the severe myalgias. Hemorrhagic dengue can result in death due to fever and shock. Diagnosis is clinical and confirmed with ELISA for IgM. Treatment is supportive with both variants.
A 20-year-old woman presents to the ED complaining of fever, chills, and migratory polyarthralgias. On physical exam, you note the lesion above. Which of the following is the most likely diagnosis? Disseminated gonorrhea Drug reaction Meningococcemia Syphilis
Correct Answer ( A ) Explanation: Disseminated gonorrhea is characteristically associated with an arthritis-dermatitis syndrome. Hematogenous spread of local gonorrhea infection occurs in 1%-2% of patients, more commonly in women, particularly those who are menstruating or peripartum. The classic skin lesion begins as erythematous or hemorrhagic papules that evolve into pustules and vesicles with an erythematous halo. The lesions are tender and may have a gray necrotic or hemorrhagic center. The lesions are often multiple and have a predilection for periarticular regions of the distal extremities. The current treatment for disseminated gonococcal infection is ceftriaxone for 7 days.
A 5-year-old boy is brought to his pediatrician's office for anal itching. His mother states the itching is worse at night and affects his sleep. His sister has similar symptoms. The pediatrician performs a cellophane-tape test, which reveals multiple elongated, ovoid eggs that are flattened on one side. Which of the following is the most appropriate treatment? Oral albendazole Oral fluconazole Topical clotrimazole Topical triamcinolone
Correct Answer ( A ) Explanation: Enterobiasis is best treated with oral albendazole. Enterobiasis, or pinworm infection, is caused by Enterobius vermicularis. Enterobiasis is the most common helminthic infection in the United States. In humans, E. vermicularis resides in the appendix, cecum, and ascending colon. At night, the gravid females travel through the rectum to lay eggs on the perianal skin. Transmission occurs via direct contact with objects contaminated with eggs. Transmission can also occur during sexual contact. While infection occurs in all socioeconomic groups, transmission is most efficient in people living in close, crowded conditions. The most common presenting symptom is perianal itching, which is caused by an inflammatory reaction to the presence of adult worms and eggs on the perianal skin. Itching often predominantly occurs at night. Secondary bacterial infections may occur if the scratching is severe. Occasionally, the worm burden becomes so high that abdominal pain, nausea, and vomiting develop. The cellophane-tape test or pinworm paddle test can be used to diagnose enterobiasis. These tests involve placing an adhesive surface against the perianal region, then examining the surface under a microscope. The test is best performed at night or early morning. Pinworm eggs have a characteristic flattened side, or "bean-shaped" appearance. Treatment consists of albendazole, mebendazole, or pyrantel pamoate. Simultaneous treatment of the entire household is typically recommended due to high transmission rates among family members. Additional measures include washing bedding and clothing, clipping fingernails, and frequent handwashing.
Which of the following is the characteristic rash associated with early Lyme disease? Erythema marginatum Erythema migrans Erythema multiforme Erythema nodosum
Correct Answer ( B ) Explanation: Erythema migrans is the primary manifestation of early Lyme disease. It usually occurs a few days to one month following an Ixodes tick bite. Typically, a red rash develops that expands gradually and often clears in the center, forming a ring. This is often referred to as a bull's eye rash. Erythema migrans may be accompanied by fever and regional lymphadenopathy and a variety of more subjective symptoms such as fatigue, malaise, lethargy, headache, neck stiffness, myalgias, and arthralgias. These flu-like signs and symptoms infrequently occur in the absence of erythema migrans
A mother presents with her 3-year-old son concerned that he has been complaining that his "bottom is itchy." Diagnostic studies confirm a pinworm infection. What is the best treatment for his condition? Albendazole Nitazoxanide Praziquantel Triclabendazole
Correct Answer ( A ) Explanation: Enterobius vermicularis, otherwise known as pinworms, are intestinal helminths transmitted via the fecal oral route. Once ingested, the worms mature in the cecum and large intestine, and the females travel to the perianal area to lay eggs. It is this process, which usually occurs at night, that causes the characteristic perianal pruritis. The itching, in turn, encourages the patient to scratch the area and increase the possibility that his unwashed hands will reinfect himself or infect someone else. Parents or caregivers may report seeing the small white worms around the perianal area, but the diagnosis is made by placing cellophane tape firmly over the perianal area. The worms and eggs may then be viewed under a microscope. Treatment is a single dose of albendazole or pyrantel pamoate by mouth. Patients and caregivers should also be counseled to avoid scratching and to change their sheets daily.
A 14-year-old boy presents with left seventh nerve facial palsy and a rash covering most of his body, diagnosed by a dermatologist as erythema migrans. He is also complaining of a headache, mild neck stiffness, myalgia, low-grade fever, malaise, and arthralgia. A large tick is removed from his scalp. Borrelia burgdorferi infection is diagnosed. Select the one finding below that is most commonly and specifically associated with Lyme disease? Erythema migrans History of a large tick bite Low-grade fever Meningitis
Correct Answer ( A ) Explanation: Erythema migrans, the characteristic skin rash of Lyme disease, occurs in two-thirds of patients with Lyme disease. The erythema expands over days, slowly clearing in the center, forming a target-like lesion around the original tick bite. As the Borrelia burgdorferi organisms disseminate, multiple lesions are formed all over the body.
An 80-year-old man presents to your clinic with complaints of malaise, myalgias, fever, cough, and abdominal pain for the past three weeks. One month ago, he vacationed in Ohio on a bird watching trip. A chest X-ray shows mediastinal lymphadenopathy and a focal infiltrate. Which of the following is the most appropriate therapy? Amphotericin B Azithromycin Fluconazole Zidovudine
Correct Answer ( A ) Explanation: Histoplasmosis is an endemic mycosis that is generally asymptomatic, but may result in serious illness in patients with certain risk factors. In the United States, histoplasmosis is most commonly found in the midwestern states near the Ohio and Mississippi River valleys. Infected soil is found near areas where bats and birds live, such as chicken coops and caves. Birds cannot be infected with histoplasmosis and are not able to transmit the disease, but their excretions contaminate the soil, which provides the growth medium for the fungus. The majority of individuals with acute and subacute pulmonary histoplasmosis are asymptomatic. When symptoms occur, patients generally present with complaints of malaise, myalgias, fever, chills, cough and abdominal pain 3-14 days after exposure. Serious manifestations of histoplasmosis occur in immunocompromised individuals, such as those with human immunodeficiency virus (HIV) or the elderly. Treatment for more serious forms of the disease is with the antifungal medication, amphotericin B
A 28-year-old woman presents your office after being bitten on her index by a special needs child who she works with. Upon examination, you note an a2 x 2 cm area of macerated skin at the medial aspect of the proximal interphalangeal joint. The patient is neurovascularly intact. Which of the following is the most appropriate next step in management to reduce the likelihood of wound infection? Copious irrigation of the wound Immediate prophylactic antibiotic therapy Radiographs of the hand to rule out presence of foreign bodies Suturing the wound and send patient home with close follow-up
Correct Answer ( A ) Explanation: Human bites may occur from accidental injuries, purposeful biting, or closed-fist injuries. These type so bites are at high risk of becoming infected due to the human mouth containing many millions of organisms per millimeter, both anaerobes and aerobes that flourish in the tartar between human teeth. Most human bite wounds involve the hands, which have high rate of infection than other locations because of the thinness of the skin overlying the structures in the hands. Human bites wounds are often polymicrobial with both aerobes and anaerobes. Commonly isolated aerobes include Eikenella corrodens and Staphylococcus, Streptococcus, and Corynebacterium species. E corrodens is frequently associated with chronic infection and abscess formation. Other commonly isolated anaerobes include Bacteroides, Fusobacteria, Prevotella, and Peptostreptococcus species. The goals of therapy are to minimize soft tissue deformity and to appropriately treat infection. It is important to recognize possible complications due to infection and start early and aggressive treatment to prevent serious wound infections and complications. Human bites have been shown to transmit systemic diseases such as hepatitis B, hepatitis C, herpes simplex virus, syphilis, tuberculosis and tetanus. The mainstay of prevention of infection is meticulous wound care with copious irrigation of the affected area. Prophylactic antibiotics are warranted especially if the hands, feet, joints or cartilaginous structures are involved. Prognosis is excellent in patients who promptly seek medical attention. Prophylactic antibiotic therapy (B) is warranted in this case, but only after wound irrigation is properly performed
A 7-year-old girl presents with the rash seen above. Her mother states it appeared 7 days after hiking through the woods near their home in New Jersey. She has no known drug allergies. Which of the following is the most appropriate treatment for this patient? Amoxicillin Azithromycin Cephalexin Doxycycline
Correct Answer ( A ) Explanation: Lyme disease is the most common vectorborne disease in the United States. It is a tickborne illness caused by the spirochete Borrelia burgdorferi. The early phase of the disease results in the characteristic rash seen above, erythema migrans. Prompt treatment of early disease can shorten the duration of symptoms and prevent progression to later stages of disease. Pregnant or lactating women and children younger than 8 years of age should receive amoxicillin. Advanced or severe disease should be treated with intravenous ceftriaxone or penicillin.
A 5-year old boy with a history of anaphylaxis to penicillin presents with exudative pharyngitis and a positive rapid antigen test for Group A Strep. What is the treatment of choice? Cefdinir Clindamycin Doxycycline Trimethoprim-sulfamethoxazole
Correct Answer ( B ) Explanation: Clindamycin provides excellent coverage for Group A Strep infections in children with immediate-type hypersensitivity reactions to beta-lactam antibiotics. The risk of resistance of Group A Strep to clindamycin is < 1%. Notably, clindamycin solution has a very harsh taste, so pills are always preferred for children who are able to swallow pills. An alternative to clindamycin is azithromycin. Cephalosporins such as cefdinir (A) are good alternatives for treatment of Group A Strep infections in patients with non-immediate hypersensitivity reactions to penicillin. However, cephalosporins are contraindicated in those with anaphylactic hypersensitivity to penicillin due to a risk of cross-reactivity between the antibiotic classes.
A 32-year-old previously healthy woman presents to your office with complaints of headache, cough and episodes of fever, shaking, chills and sweating. She tells you that she was recently on a mission trip to Haiti and did not see a medical provider before her trip. Lab work is ordered and testing identifies Plasmodium falciparum on blood smear. Which of the following is the most appropriate therapy? Chloroquine Doxycycline Isoniazid Supportive care
Correct Answer ( A ) Explanation: Malaria is a mosquito-borne infection that is potentially fatal. The infection is caused by the Plasmodium protozoa and is transmitted by an infected female Anopheles mosquito. Cases of malaria in the United States are seen in patients who have traveled to malaria-endemic countries. Malaria is most prevalent in rural regions of countries with tropical climates. Patients planning a trip to a malaria-endemic region should be advised to take malaria prophylaxis to prevent infection. Clinical presentation includes several fever spikes per day, headache, cough, malaise, arthralgia, myalgia, chills and sweats. Diagnosis is made when the parasite is seen on blood smear with light microscopy. Regions where chloroquine-sensitive malaria is found include Haiti, the Dominican Republic, and certain parts of Central America. When infection with chloroquine-sensitive malaria is likely, treatment with the antimalarial agent chloroquine should be administered.
Which of the following is an indication for prophylaxis against Pneumocystis jirovecii pneumonia in individuals infected with HIV? CD4 count of 125 CD4 count of 1500 Individuals taking anti-retroviral therapy Pregnant women with HIV regardless of CD4 count
Correct Answer ( A ) Explanation: Pneumocystis jirovecii pneumonia (PCP), previously called Pneumocystis carinii pneumonia, is the most common cause of death in individuals with AIDS-related complications. Primary prophylaxis is indicated when CD4 counts fall below 200. Risk factors for the development of this opportunistic infection include a history of PCP, decreased CD4 count, as well as undiagnosed weight loss, oropharyngeal candidiasis, night sweats and fever in individuals with CD4 counts above 200 cells. Definitive diagnosis is by cytopathologic or histopathologic evidence of the organism in induced sputum samples, bronchoalveolar lavage fluid, or tissue. Trimethoprim-sulfamethoxazole is the recommended medication for prophylaxis and is also used for treatment of the disease.
Which of the following is an absolute contraindication to the measles, mumps and rubella vaccine? Anaphylactic reaction to neomycin Family history of seizure History of autism History of immune thrombocytopenia
Correct Answer ( A ) Explanation: Prevention against measles, mumps and rubella (MMR) is provided by two doses of a live-virus vaccine. The recommended schedule is the first dose at ages 12-15 months and the second dose at school entry, between ages 4-6 years. The MMR vaccine contains trace amounts of neomycin, therefore patients with a history of anaphylaxis to neomycin should not receive it. Other true contraindications include previous severe allergic reaction to any component of the vaccine, individuals who are immunocompromised, pregnancy, hematologic or solid tumors, and HIV infection with immunosuppression.
What is the most common carrier of rabies in the United States? Bats Cats Raccoons Squirrels
Correct Answer ( A ) Explanation: Rabies is a viral disease transmitted by the bite of a rabid animal that results in encephalopathy and near-certain death. While any mammal can carry rabies, in the United States more than 90% of all cases occur in wild animals. Bats (A) are the most common carrier, followed by raccoons, skunks, and foxes. Worldwide, dogs are the most commonly infected animal. Mice, rats, squirrels, and rabbits are unlikely to be carriers and there has never been a known case of rabies transmitted to a human from one of these animals.
A 27-year-old pregnant woman presents to your office with questions about travel preparation. She is planning a six-month mission trip to Ghana and wants to know if she needs any medical care prior to leaving. Which of the following is the most appropriate next step in management? Advise patient to delay trip until after delivery Advise patient to use mosquito bite prevention Prescribe malaria prophylaxis with chloroquine Prescribe malaria prophylaxis with doxycycline
Correct Answer ( A ) Explanation: Risk factor assessment is an important aspect of counseling patients who plan to travel abroad. Geographic location and the type of traveler are both factors to be considered, especially with regards to advising about malaria prophylaxis. The Centers for Disease Control provides a helpful website with country and risk for malaria that may be referenced when counseling patients about the need for malaria prophylaxis. High-risk groups include pregnant women, military personnel and individuals born in regions endemic to malaria who relocate to another region then return to visit their native country. Because malaria is a life-threatening illness for both mother and fetus, pregnant patients should be advised to delay their trip until after delivery. Mosquito bite prevention (B) is an important part of malaria prevention and should be advised for all patients traveling to malaria endemic areas. Techniques to prevent mosquito bites should be used together with malaria prophylaxis for non-pregnant patients traveling to these countries. Chloroquine-resistant malaria (C) is common in both Africa and Asia. The most recent advisories should be consulted prior to determining an appropriate course of prophylaxis. Doxycycline (D) is a daily medication used for malaria prophylaxis in areas with chloroquine-resistant malaria. Patients begin taking it 1-2 days prior to exposure, then continue daily during exposure and for 4 weeks post-exposure. Doxycycline should not be administered during pregnancy due to potential adverse affects to the fetus.
Which of the following has the highest prevalence of rabies proportional to its population size in the United States? Bats Dogs Raccoons Skunks
Correct Answer ( A ) Explanation: Since the 1950s, rabies in U.S. domestic animals has decreased significantly, but the population of rabid wild animals has actually increased. The primary reservoirs are bats (31%), raccoons (29%), skunks (25%), and foxes (6%)
Which of the following statements is true regarding the diagnosis of Epstein-Barr virus infection? Guillain-Barré syndrome is a possible complication Neutrophilia predominates Splenomegaly occurs in 10% of patients The virus is transmitted via respiratory droplets
Correct Answer ( A ) Explanation: The Epstein-Barr virus (EBV) is implicated in a variety of human illnesses. It is associated with infectious mononucleosis, B-cell lymphoma, Hodgkin disease, Burkitt lymphoma, and nasopharyngeal carcinoma. EBV can affect nearly all organ systems. Neurologic complications such as encephalitis, meningitis, and Guillain-Barré have been reported. EBV is associated with lymphocytosis (B) with > 50% lymphocytes. Atypical lymphocytes are found on examination of the peripheral blood smear. Splenomegaly (C) occurs in > 50% of patients. Therefore, patients should be advised to avoid all contact sports for a minimum of four weeks after illness onset to avoid splenic injury. EBV is transmitted via salivary secretions (D) and requires close contact for transmission (hence lay application of the term "kissing disease"). The infection is usually contracted from an asymptomatic individual who sheds the virus. After infecting the oropharyngeal epithelium, it disseminates through the blood stream. The virus infects B lymphocytes and causes an increase in T lymphocytes, which results in enlargement of lymphoid tissue. In immunocompromised patients with decreased T-cell function, B cells continue to proliferate, and proliferation may lead to neoplastic transformation.
Which of the following patients has a positive Mantoux test? A 32-year-old immunocompetent male with 15 mm induration A 36-year-old HIV+ female with 6 mm of erythema but no induration A 42-year-old male who previously received Bacille Calmette-Guérin (BCG) immunization against tuberculosis with 10 mm induration A 51-year-old female IV drug abuser with <5 mm induration
Correct Answer ( A ) Explanation: The Mantoux test is used to screen for tuberculosis exposure. Tests are administered to individuals at high risk for latent TB infection, including healthcare workers. Testing is performed by injecting 0.1 mL of purified protein derivative (PPD) into the forearm. At 48-72 hours, this injection site is assessed for induration. Induration is the result of a delayed hypersensitivity reaction. Positive results vary depending upon the individual's risk factors for tuberculosis. Patients with > 5 mm induration who are HIV+, have close contact with someone with active infection, have previous chest x-ray findings suggestive of healed infection or have organ transplants, and are on immunosuppressive agents are considered positive. Patients with > 10 mm induration who abuse IV drugs, are immigrants from endemic areas of the world, are residents of long-term care facilities, or are under the age of four years are considered positive. Patients with > 15 mm induration in otherwise healthy, immunocompetent adults are considered positive.
You see a 15-month-old girl in the clinic for a well child visit. She likes to listen to her parents read bedtime stories to her. She can show you what she wants by pointing and pulling on things. She can also speak two words. You hand her a crayon, which she grabbed onto and started scribbling. She is also walking well. The mother is concerned because yesterday she was exposed to her four-year-old cousin who was febrile and later confirmed to have influenza B. Which of the following is the next best step? Administer oseltamivir Give amantadine No treatment necessary Prescribe amoxicillin-clavulanic acid
Correct Answer ( A ) Explanation: The girl has been exposed to her cousin confirmed to have influenza during the infectious period (one day before the onset of symptoms until 24 hours after the fever ends). Since the girl is younger than two years of age and is therefore at high risk for complications to influenza, post-exposure chemoprophylaxis is warranted. Certain groups of children are at increased risk of acquiring severe or complicated illness from influenza. These include children younger than two years of age, adults greater than 65 years of age, persons with chronic illnesses, pregnant women, children less than 19 years on chronic aspirin therapy, and immunosuppressed individuals. Post-exposure prophylaxis should be used only when antivirals can be started within 48 hours of the most recent exposure. Oseltamivir and zanamivir are used for chemoprophylaxis. These drugs significantly diminish influenza illness among household and hospital contacts of patients with laboratory-confirmed influenza. Nonetheless, patients should be informed that chemoprophylaxis lowers, but does not eliminate, the risk of influenza, that susceptibility to influenza returns once the antiviral medication is stopped, and that immunization remains the primary means of protection.
Which of the following is true regarding the condition seen in the images above? The causative organism is spread via the fecal-oral route The illness occurs most frequently in the winter months Treatment is with antiviral medications Vaccination prevents the disease
Correct Answer ( A ) Explanation: The lesions are manifestations of hand-foot-and-mouth disease, a viral infection caused by coxsackievirus. Toddlers and school-age children are most commonly affected. Transmission is by the fecal-oral route and usually occurs in the summer and fall months in crowded places where children congregate such as a swimming pool. It is characterized by a prodrome of fever, malaise, sore throat, and anorexia over a couple of days, followed by the appearance of the characteristic rash. The location of the lesions involve the following: (1) hands and palms (dorsal and palmar surface, sides of fingers); (2) sides of feet and toes, soles (plantar surface); (3) usually the anterior portion of the mouth, most frequently the tongue and buccal mucosa, hard palate, gingivae, and lips. The most frequent site of the lesions is the mouth and the hands are more frequently involved than the feet. The mouth lesions begin as small red macules or papules that turn into vesicles then ulcerate and crust. The extremity lesions are vesicular and pink to red in appearance.They are typically distributed bilaterally and symmetrically on the hands and feet. The skin lesions may be asymptomatic or painful, while the mouth lesions are almost always painful. Treatment is supportive with oral fluids and antipyretics. In most cases, the course is self-limited, resolving in 7-10 days. Herpangina is a characteristic enanthem produced by several enteroviruses, with coxsackie A, B, and echovirus being the most common. This condition is characterized by oral lesions that usually appear in the posterior aspect of the mouth, specifically on the anterior tonsillar pillars (most common), posterior pharyngeal wall, soft palate, tonsils, uvula, and occasionally the posterior buccal mucosa. Herpangitis is rarely associated with aseptic meningitis or other severe enteroviral illnesses.
A 17-year-old man presents with a "bump" on his penis. He denies other symptoms, significant past medical history, or recent travel. He has had a new sexual partner for the past three weeks, but she has not had reported symptoms. Exam reveals an erythematous but non-tender papule with slight ulceration at its center. What is the treatment of choice? Intramuscular benzathine penicillin G Intramuscular ceftriaxone Oral acyclovir Oral azithromycin in a single dose
Correct Answer ( A ) Explanation: The patient has the typical presentation of a chancre, which is caused by Treponema pallidum. A painless chancre is the hallmark of primary syphilis and appears two to three weeks after inoculation with bacteria. In immunocompetent hosts, it begins as a single papule, which then ulcerates at its center, leaving behind raised edges. The ulcer is typically non-exudative. Many patients also develop bilateral inguinal lymphadenopathy. Because the chancre is painless, it may not be noticed by the patient or brought to medical attention prior to self-resolution. Untreated, the patient will transition into latent syphilis and has a 25% chance of developing symptoms of secondary syphilis. The treatment of choice for primary syphilis is intramuscular benzathine penicillin G. Benzathine penicillin remains detectable in serum for up to thirty days after administration. Treatment with shorter-acting penicillins are associated with treatment failure and thus is not recommended.
Which of the following patients requires human rabies immune globulin? A person who was not previously vaccinated awakens to find a bat in his room and animal not captured A person who was previously vaccinated was bit by a dog and animal not captured A person who was previously vaccinated was bit by a fox and animal not captured A person who was previously vaccinated was bit by a rat and animal not captured A person who was previously vaccinated was bit by a squirrel and animal not captured
Correct Answer ( A ) Explanation: The question as to which patient requires human rabies immune globulin and human rabies vaccine after exposure to a potentially rabid animal is common in emergency medicine. Even though there was no clear bite or abrasion, the Advisory Committee on Immunization Practices (ACIP) recommends postexposure prophylaxis with immune globulin and vaccine for unvaccinated patients who have been in close proximity to bats, even if there is no sign of injury or damage to the skin, including waking up and finding a bat in the room. In an unvaccinated individual, this means human rabies vaccine and immune globulin given at the time of presentation.
22-year-old old man presents to his primary care provider for genital warts that appeared several months ago and have progressively grown. His girlfriend has similar lesions on her vulva. Physical exam reveals multiple, soft, skin-colored filiform masses on the glans penis. There are also grouped lesions around the man's anus as shown above. Which of the following is the most likely diagnosis? Condylomata acuminata Condylomata lata Moluscum contagiousum Seborrheic keratoses
Correct Answer ( A ) Explanation: This man most likely has condylomata acuminata, or anogenital warts. Condylomata acuminta is caused by the human papillomavirus (HPV), a double-stranded DNA virus. HPV is the most common viral sexually transmitted infection. The majority of condylomata acuminata cases are caused by HPV subtypes 6 and 11. HPV subtypes 16 and 18 are most commonly associated with squamous cell carcinoma and squamous high-grade intraepithelial neoplasia. HPV is transmitted through sexual intercourse and occasionally through fomites. Most patients are asymptomatic. Symptoms of anogenital warts include pruritus, bleeding, burning, and tenderness. Lesions are skin-colored or pink and range from smooth, verrucous, filiform, or lobulated. Eruptions typically appear on the penile glans and shaft in men and vulvovaginal and cervical areas in women. The diagnosis of condylomata is typically made on physical exam. Biopsy may be used when the diagnosis is unclear. The three major treatment approaches of condyloma acuminatum are chemical or physical destruction, immunologic therapy, and surgery. Chemical agents include podophyllin, trichloroacetic acid, and 5-fluorouracil. Podophyllin is contraindicated for use in pregnant patients and is not recommended for patient-applied use. Podophyllin should never be applied to the cervix or vaginal epithelium. Trichloroacetic acid can be used for internal lesions and during pregnancy. Surgical removal should be considered when medical therapy has failed or as an initial approach for very large lesions. The human papillomavirus vaccine has been shown effectively prevent HPV infections in men and women. Condylomata lata (B) is caused by secondary syphilis infection. Condylomata lata lesions appear flat, velvety, and moist. These lesions often occur in areas close to the primary chancre. Syphilis is caused by the bacterium Treponema pallidum.
A 27-year-old previously healthy man visiting the United States from Guatemala presents to the ED with acute dyspnea. He reports feeling well until about one week ago. Vital signs are BP 110/70 mm Hg, HR 120, RR 26, T 38.3°C, and pulse oximetry of 93% on room air. On exam, you note facial and lower extremity edema, hepatosplenomegaly, and lymphadenopathy. What is the most likely diagnosis? Chagas disease Dressler's syndrome Kawasaki's disease Takotsubo cardiomypathy
Correct Answer ( A ) Explanation: This patient has Chagas disease, which is caused by the parasite Trypanosoma cruzi. The parasite is transmitted through the bite of the reduviid (kissing bug) and is endemic in South and Central America. Acute myocarditis is a common complication of Chagas disease and may manifest with acute heart failure (as in this example) or arrhythmia (often refractory to rate control). Acute infection is associated with fever, edema, hepatosplenomegaly, lymphadenopathy, malaise, lymphocytosis, and elevated liver transaminases. In 25% of cases, acute infection progresses to chronic disease, typically with cardiac (dilated cardiomyopathy) or gastrointestinal (megaesophagus and megacolon) involvement.
A 26-year-old woman presents to the ED after finding a tick attached to her right flank. She believes it has been there since she went hiking four days prior. On exam, you notice a red annular rash on her right flank with mild central clearing. A urine beta-hCG test is positive. Her last menstrual period was six weeks prior to this visit. What antibiotic prescription should this patient receive? Amoxicillin, 14 days Doxycycline, 14 days Doxycycline, 7 days Trimethoprim-sulfamethoxazole, 14 days
Correct Answer ( A ) Explanation: This patient has a history and physical exam consistent with Lyme disease. Her rash is classic for erythema chronicum migrans, seen in 60%-80% of those with Lyme disease, usually in the first several days after a tick bite. This first stage of Lyme disease needs to be treated before it progresses to more serious symptoms affecting the neurological and cardiovascular systems. She is also pregnant; therefore, she should be treated with a 14-day course of amoxicillin.
A G1P0 27-year-old woman at 12 weeks gestation presents to the Emergency Department with the above physical exam finding after hiking through the woods in Wisconsin. What is the most appropriate therapy? Amoxicillin 500 milligrams orally three times daily Ceftriaxone 1 gram intravenously every 12 hours Doxycycline 100 milligrams orally two times daily Rifampin 600 milligrams orally once daily
Correct Answer ( A ) Explanation: This patient is exhibiting erythema migrans, a hallmark of Lyme disease. Lyme disease is the most common vector-borne disease in the United States. It is endemic to New England, the mid-Atlantic states, and the upper Midwest. It is caused by the spirochete Borrelia burgdorferi and transmitted by the Ixodes dammini tick, more commonly known as the deer tick. The tick must be attached for more than 48 hours for transmission to occur. There are three stages of clinical Lyme disease. Early Lyme disease is characterized by erythema migrans, an erythematous blanching patch than may have central clearing and classically has a "bull's eye" appearance. Hematogenous spread leads to diffuse erythema migrans, which spares the palms and soles. Acute disseminated Lyme disease occurs approximately four weeks after initial infection and can include meningoencephalitis, Bell's palsy (which may be bilateral), or carditis which often manifests with AV block. Late Lyme disease develops greater than one year after initial infection and includes chronic arthritis with or without chronic subtle encephalopathy. Only 50% of patients remember a tick bite; thus, diagnosis may be difficult. Erythema migrans is diagnostic; however, not all patients present with this finding. Initial screening involves ELISA testing with Western Blot and PCR to confirm the diagnosis. If the diagnosis is suspected, empiric treatment should be administered. Treatment for early Lyme disease and mild acute disseminated Lyme disease in pregnant women or children under the age of eight years is amoxicillin 500 mg PO three times daily.
A previously healthy 18-year-old woman presents with sore throat and pain with swallowing. Her vital signs are T 102.7°F, HR 124, BP 123/76, RR 22, and oxygen saturation 97%. On examination she has trismus, pain with neck extension, and difficulty swallowing her saliva. Her oropharyngeal examination is unremarkable. Which of the following is the most appropriate next step in management? CT scan of the neck with contrast and ENT consultation Ibuprofen, dexamethasone, and a Rapid strep test Oral antibiotics and ENT follow up Peritonsillar needle aspiration
Correct Answer ( A ) Explanation: This patient is suffering from a retropharyngeal abscess and will need advanced imaging (CT scan of the neck with IV contrast) to further delineate the extent of the disorder along with emergent ENT consultation for possible operative intervention. Historically, this was a disease of children under 6 years of age but adults are increasingly affected. A number of infectious processes including nasopharyngitis, otitis media, peritonsillar abscess, dental infections as well as iatrogenic procedures including endoscopy and dental instrumentation have been associated with retropharyngeal abscess formation. The infection is most commonly polymicrobial with both aerobes and anaerobes requiring broad antibiotic coverage. Patients typically present with sore throat, odynophagia, dysphagia, drooling, muffled voice, neck stiffness, fever and trismus. In severe cases, the patient may hold the neck in extension in order to increase airway diameter by distracting the posterior pharynx from the airway. CT scan and MRI are diagnostic but in unstable patients, lateral neck X-ray can demonstrate retropharyngeal swelling supporting the diagnosis. Additionally, if the patient is unable to lie flat for advanced imaging, direct visualization with an upper airway scope can be diagnostic.
Bilateral facial nerve palsy in children is pathognomonic for which of the following conditions? Guillian-Barré Lyme disease Myasthenia gravis Systemic lupus erythematosus
Correct Answer ( B ) Explanation: Bilateral facial nerve palsy is virtually pathognomonic for Lyme disease in children. Cranial nerve palsy of cranial nerve VII (facial nerve) is a common manifestation of Lyme disease in children. Factors associated with Lyme disease include fever, headache, and absence of history of herpetic lesions. The palsy in Lyme disease may be a result of mononeuritis multiplex, which is a peripheral neuritis, or of basilar meningitis with involvement of the facial nerve. Facial nerve palsy associated with Lyme disease usually resolves completely with or without antimicrobial therapy. Antimicrobial therapy is necessary to prevent other manifestations of Lyme disease, including late cardiovascular and neurological complications. Guilian-Barré (A) is associated with ascending paralysis. Myasthenia gravis (C) is associated with ptosis, which is the inability to open the upper eyelids. Systemic lupus erythematosus (D) is associated with a facial malar rash. Bilateral nerve palsy is not pathognomonic for any of these conditions
A 19-year-old sexually active woman comes to your office for a routine checkup. She is generally healthy with no chronic conditions and does not smoke. Which of the following conditions should you perform a screening test for? ACervical cancer BChlamydia infection CHuman Papillomavirus (HPV) DHypercholesterolemia
Correct Answer ( B ) Explanation: According to the U.S. Preventive Services Task Force (USPSTF), there is good evidence that screening for Chlamydia infection in women who are at increased risk can reduce the incidence of pelvic inflammatory disease, while the harms are minimal. The evidence regarding screening under age 21 for cervical cancer (A) with Pap testing or human papillomavirus (HPV) (C) testing, however, shows that the harms outweigh any possible benefits. Harms include over diagnosis and over treatment, including invasive cervical procedures that can affect future pregnancy outcomes. In addition, there is adequate evidence that screening women younger than 21 years of age (regardless of sexual history) does not reduce the incidence of cervical cancer or mortality compared with beginning screening at age 21. The USPSTF concludes that the evidence is insufficient to recommend for or against routine screening for lipid disorders (D).
24-year-old sexually active man presents with complaints of the "flu" for the past three weeks. Specifically, he complains of generalized weakness, malaise, myalgias, a low-grade fever, and anorexia. He denies URI symptoms or a cough. He has intercourse with men and does not always use condoms. He is concerned that he may have contracted HIV. His vital signs are significant for a blood pressure of 128/62 mm Hg, a heart rate of 82 beats per minute, an oxygen saturation of 99% on room air, and a temperature of 38.5°C. Your physical exam reveals a well-appearing male who is in no acute distress with no thrush or abnormal findings. Laboratory values reveal WBC of 6.2 with 3% bands, hemoglobin of 15.6 g/dl, and platelets of 120. Chest radiograph and urinalysis are normal. Which of the following statements best describes the next management step? You suspect acute HIV syndrome, obtain an oral swab for rapid HIV testing, and admit the patient for confirmatory studies if positive You suspect acute HIV syndrome, obtain an oral swab for rapid HIV testing, and confirm with blood specimen if positive You suspect acute HIV syndrome, obtain an oral swab for rapid HIV testing, and discharge and reassure the patient if negative You suspect acute HIV syndrome, obtain an oral swab for rapid HIV testing, and make the diagnosis of HIV if positive
Correct Answer ( B ) Explanation: Acute HIV syndrome (also known as acute seroconversion syndrome) may follow primary exposure by two to four weeks and cause nonspecific symptoms, including fever, chills, malaise, myalgias, pharyngitis, diarrhea, or other neurologic or immunologic complaints. These symptoms are generally mild with spontaneous resolution and are often mistaken for a benign viral illness. As a result, many patients do not seek medical care during this phase. When testing for HIV, positive oral swab results should be considered preliminary pending confirmation (required) with serum testing via HIV-1/HIV-2 differentiation immunoassay or Western blot.
An 8-year-old boy is brought to the ED by his parents after they discovered a tick attached to his right armpit. What is the best way to remove the tick? Coat the tick in petroleum jelly Grab as close to the tick's head with forceps and pull upward Immerse the tick in isopropyl alcohol Immerse the tick in normal saline Tie a suture around the tick's body and pull upward
Correct Answer ( B ) Explanation: Although many techniques have been described over the years for removing a tick, the correct method is to use tweezers or forceps, grab the tick's head as close to the skin as possible, and gently pull upward. The goal is to avoid crushing or tearing the tick's head or body because this can induce regurgitation of infectious contents or leave behind its body parts, a possible nidus for infection or a granulomatous reaction.
An 8-year-old girl presents with fever, malaise and headache. On exam, she has left-sided tender axillary lymph nodes and the lesion seen above on her wrist. Which of the following is the most likely diagnosis? Brucellosis Cat scratch disease Toxoplasmosis Tularemia
Correct Answer ( B ) Explanation: Cat scratch disease is caused by Bartonella henselae which is transmitted by cat scratches (most often by kittens). In most cases, patients first present with an erythematous crusty lesion at the site of the inoculation 3 to 12 days after a scratch. One to three weeks after this primary lesion, regional lymphadenopathy appears, most commonly in the axillary, cervical and inguinal nodes and is often painful or suppurative. Patients may also develop fever, malaise, headache, and anorexia. Rare complications include bacillary angiomatosis (mainly in immunocompromised individuals), hepatosplenomegaly, encephalopathy, pneumonitis, myelitis, joint pain, parinaud oculoglandular syndrome (unilateral conjunctivitis with per-auricular lymphadenitis), neuroretinitis, and abdominal pain. Bartonella is difficult to culture and so serologic testing is the preferred method. Polymerase chain reaction may also be used but is less sensitive. Management is mainly supportive with antipyretics and analgesics. Antibiotics are indicated in immunocompromised patients or severe cases. First line drugs include trimethoprim-sulfamethoxazole, ciprofloxacin and azithromycin. Brucellosis (A) is caused by the ingestion of unpasteurized milk or undercooked meat contaminated with the gram negative bacteria Brucella. Symptoms include joint and muscle pain, profuse sweating, and fever. Toxoplasmosis (C) is caused by Toxoplasma gondii, an intracellular parasite, acquired from the ingestion of cysts in undercooked meat, through gardening, or from cat feces. Symptoms can be flu-like or involve cysts in nervous and muscle tissue, prurigo-like nodules, ecchymoses, urticaria and maculopapular lesions. Tularemia (D) is caused by Francisella tularensis which is transmitted by ticks and deer flies on rabbits and rodents. Symptoms include skin ulcers, lymphadenitis, headache, fever, fatigue, eye symptoms, vomiting, pharyngitis, hepatosplenomegaly and cough.
Which of the following activities carries the highest risk for infection with human immunodeficiency virus ? ABeing bitten by a mosquito that previously bit an HIV-positive individual BReceptive anal intercourse with a individual who is HIV-positive CReceptive oral intercourse with an individual who is HIV-positive DReceptive vaginal intercourse with an individual who is HIV-positive
Correct Answer ( B ) Explanation: HIV is a blood-borne RNA virus of the Ketroviridae family, Lentivirus genus. Two distinct species, HIV-1 and HIV-2 are responsible for disease, but HIV-1 is the predominant strain seen in developed countries. HIV may be transmitted sexually by exposure of mucosal surfaces to infected genital secretions, parenterally by sharing of contaminated needles in injection drug use or via contaminated blood products, or vertically from mother-to-child during birth or breastfeeding. Sexual transmission is the most common means of transmission of HIV. Worldwide, the most common epidemiological pattern is heterosexual transmission. In the United States, male-to-male sexual transmission is a more common, representing 67% of new cases compared to 27% from heterosexual contact. Receptive anal intercourse with an HIV-positive individual is highest risk for transmission of the virus, followed by receptive vaginal intercourse.
Which of the following best describes the most common symptoms of acute human immunodeficiency virus infection? Diarrhea and abdominal pain Fever, malaise, myalgias, sore throat, and rash Fever, productive cough, and shortness of breath Most individuals are asymptomatic
Correct Answer ( B ) Explanation: In the United States, an estimated 1.2 million individuals are HIV positive, with approximately 50,000 people newly diagnosed each year. The clinical presentation of acute HIV infection, also known as acute retroviral syndrome, is variable both in type and severity of symptoms. The classic presentation is abrupt onset of a viral-like illness, which develops 10 to 14 days following exposure to the virus. Symptoms may include fever, malaise, sore throat, headache, arthralgias, anorexia, nausea, vomiting, and rash. Physical examination findings vary and may include generalized lymphadenopathy, nonexudative pharyngitis, mild hepatosplenomegaly, mucocutaneous ulcers, and oral thrush. A maculopapular rash on the thorax, face, and limbs may also be present. Due to the nonspecific and self-limited nature of symptoms, many affected individuals do not seek care and thus the true incidence of acute HIV is unknown. However, experts estimate that 60 to 90 percent of individuals who contract HIV develop an acute illness. Identification of acute HIV has tremendous public health implications, as acute infection represents the peak infectivity of the disease, characterized by high levels of viral shedding. Routine HIV tests used in most emergency departments measure anti-HIV antibodies, which are often falsely negative during acute infection. Therefore, when acute HIV is suspected, nucleic acid amplification tests, which directly measure viral RNA in the patient's blood, should be used.
A tuberculin skin test is performed on a medical professional who works full time in a correctional institute. The test is performed on the volar surface of the patient's forearm. Sixty hours later, the transverse width of the induration at the skin test site is measured in millimeters. Which of the following induration sizes represents a the cutoff for a positive reaction in this type of patient? 1 mm 10 mm 15 mm 5 mm
Correct Answer ( B ) Explanation: Induration width of 10 mm is considered a positive reaction in the following groups: (i) recent immigrants from countries with a high prevalence of tuberculosis, (ii) injection drug users, (iii) personnel working in a mycobacteriology laboratory, (iv) residents and employees in high-risk congregate settings, including correctional institutes, nursing homes, hospitals, other health care facilities, and homeless shelters, (v) patients with other medical conditions that increase the risk of tuberculosis, including diabetes mellitus, silicosis, chronic kidney disease, gastrectomy, more than 10% below ideal body weight, leukemia, lymphoma, carcinoma of the neck, head or lung, and (vi) children under 4 years old or any children exposed to adults at high risk.
In an adult patient who is otherwise asymptomatic and identifies an engorged tick that has been attached for longer than 36 hours, what is the most appropriate medication for prophylaxis of Lyme disease? Clindamycin Doxycycline Penicillin Vancomycin
Correct Answer ( B ) Explanation: Lyme disease is transmitted by the bite of an Ixodes scapularis tick and is the most common vectorborne disease in the United States. Doxycycline is the drug of choice for prophylaxis against Lyme disease in an adult patient who is not pregnant and living in an endemic area. Nadelman and colleagues have reported that the administration of the medication within 72 hours of the time the tick was removed significantly reduces the likelihood of contracting Lyme disease.
Which of the following anatomical structures is most commonly affected by Rubulavirus? Pancreas Parotid glands Sublingual glands Testes
Correct Answer ( B ) Explanation: Mumps is an acute viral illness caused by the RNA virus, Rubulavirus. Transmission is through respiratory droplets, fomites, or direct contact. It is extremely contagious and can spread rapidly among people sharing close quarters. The characteristic clinical manifestation of mumps is the swelling of salivary glands, most typically the parotid glands. Other symptoms include fever, malaise, headache, and ear pain. Mumps cases have decreased significantly due to widespread vaccination programs, although sporadic outbreaks can occur. Diagnosis is based on the presence of parotiditis along with a history suggestive of mumps. The course of illness is self-limited, with treatment being supportive measures, including ibuprofen or acetaminophen. Prevention of illness is through immunization with the mumps vaccine
A 28-year-old man presents to your office for follow up on a positive HIV test. He has never taken antiretroviral medications and his CD4 count is 610 cells/mm3. Which of the following medication regimens do you begin? 1 nucleoside/nucleotide reverse transcriptase inhibitor and 1 non-nucleoside reverse transcriptase inhibitor 2 nucleoside/nucleotide reverse transcriptase inhibitors and 1 non-nucleoside reverse transcriptase inhibitor 2 protease inhibitors and 2 non-nucleoside reverse transcriptase inhibitors The patient does not need antiretroviral therapy at this time due to a high CD4 count
Correct Answer ( B ) Explanation: The United States Department of Health and Human Services recommends an initial antiretroviral regimen for HIV treatment-naïve patients that includes two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) with a third agent from one of the following drug classes: a non-nucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor boosted with ritonavir or an integrase inhibitor. Regimen selection is made on an individualized basis after consideration of pill burden, drug interactions, comorbid conditions, cost and resistance testing results.
A 32-year old teacher is seen for a paroxysmal cough of 5 days' duration. He tells you that a student in his class was diagnosed with pertussis 3 weeks ago. Which one of the following is the best treatment? Amoxicillin Azithromycin Cephalexin Trimethoprim/sulfamethoxazole
Correct Answer ( B ) Explanation: Pertussis, also known as whooping cough, is an acute respiratory tract infection that has increased in incidence in recent years. The initial catarrhal stage presents with nonspecific symptoms of malaise, rhinorrhea, sneezing, lacrimation, and mild cough. During the paroxysmal stage, severe outbreaks of coughing often lead to the classic high-pitched whooping sound patients make when gasping for breath. The paroxysmal stage is followed by the convalescent stage and resolution of symptoms. Complications vary by age, with infants more likely to experience severe complications such as apnea, pneumonia, seizures, or death. In adolescents and adults, complications are the result of chronic cough. The diagnosis depends on clinical signs and laboratory testing. Both culture and polymerase chain reaction testing can be used to confirm the diagnosis. Although antibiotics have not shown clear effectiveness in the treatment of pertussis, they eradicate nasal bacterial carriage and may reduce transmission rates. Macrolide antibiotics such as azithromycin are first-line treatments to prevent transmission. Immunization against pertussis is essential for disease prevention. Current recommendations in the United States consist of administering five doses of the diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine to children before seven years of age, and administering a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) booster between 11 and 18 years of age.
Which of the following is an absolute contraindication for the mumps, measles, rubella (MMR) vaccine? Current minor upper respiratory infection Pregnancy Sibling with a history of febrile seizures Sibling with autism
Correct Answer ( B ) Explanation: Pregnancy is an absolute contraindication for the mumps, measles, rubella (MMR) vaccine. Other absolute contraindications include women intending to become pregnant within one month, immunocompromised patients, patients on high dose steroids and patients with severe allergies to previous MMR vaccination or neomycin.
Which of the following can cause a false positive rapid plasma reagin (RPR)? Aspirin use Autoimmune disease Owning a pet cat Young age
Correct Answer ( B ) Explanation: Rapid plasma reagin (RPR) is a diagnostic test that looks for non-specific antibodies to Treponema pallidum, the organism that causes syphilis. The RPR test has a high sensitivity but low specificity. False positives are seen in individuals with autoimmune disease, viral infections (EBV, hepatitis, varicella, measles), lymphoma, malaria, connective tissue disease, pregnancy, older age, and IV drug abuse. As a result of the low specificity, a positive RPR should always be followed up by a more specific treponemal test such as Treponema pallidum hemagglutination assay (TPHA) and Fluorescent Treponemal Antibody Absorption (FTA-ABS). The Venereal Disease Research Laboratory (VDRL) test is also sometimes used as a screening test but the RPR test is generally preferred due to its ease of use.
A 19-year-old woman presents with four days of high fever, headache, myalgias. She also developed blanching erythematous rash with macules on her wrists and ankles that spread to her trunk. She denies history of distant travel but was camping last weekend at a local state park in North Carolina. Which of the following is the most appropriate treatment? Ceftriaxone Doxycycline Erythromycin Vancomycin
Correct Answer ( B ) Explanation: Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by Rickettsia rickettsii. Following a tick bite, the incubation period ranges from two days to two weeks. Patients will present with an abrupt onset of fever, severe headache, myalgias, and nausea and vomiting. Fever is nearly always present in the first few days of illness and may precede other symptoms by a week or more. The rash is the result of vascular endothelial damage and usually appears on the third to fifth febrile day of the illness. The rash is seen first on the wrist and ankles (with involvement of the palms and soles in 50% of cases) and initially is a blanching, nonpalpable, discrete macular rash. Within hours, the rash spreads to the extremities and trunk. Within a few days, the rash becomes petechial and no longer fades. Patients will usually have a normal white blood cell count, but may be thrombocytopenic. Treatment includes doxycycline (even for children) and supportive care. Chloramphenicol is an alternative antibiotic that can used in patients with severe allergy or pregnant women
A 65-year-old man with cirrhosis and ascites presents to the emergency room with diffuse abdominal discomfort, fever, and altered mental status. His home medications include furosemide and spironolactone. On physical exam he is febrile and his abdomen is mildly tender with positive shifting dullness and fluid wave. You perform a diagnostic paracentesis. Which of the following findings best supports your diagnosis? Bloody appearance of ascites Neutrophil count > 250 pH > 7.34 Polymicrobial growth on ascitic culture
Correct Answer ( B ) Explanation: Spontaneous bacterial peritonitis (SBP) is an infection of ascitic fluid that cannot be attributed to any other intrabdominal conditon. It is one of the most common bacterial infections in patents with cirrhosis and should always be at the top of the differential when examining a tender abdomen in the presence of ascites in a febrile patient. A peritoneal fluid absolute neutrophil count greater than 250 cells is the accepted criterion for the diagnosis of spontaneous bacterial peritonitis. Gram-negative bacteria are the most common pathogens causing spontaneous bacterial peritonitis and most are difficult to culture, therefore a positive culture is not needed for the diagnosis. Treatment is directed primarily at early administration of empiric antibiotics for the duration of 7-10 days
An 84-year-old woman with new onset altered mental status is sent to the ED from her assisted living facility. According to the facility staff, she has had a productive cough for two days. Her vital signs are blood pressure 90/60 mm Hg, heart rate 92 beats per minute, respiratory rate 25 breaths per minute, temperature 38.3°C, and oxygen saturation 95% on room air. Laboratory results reveal a WBC of 11,000. A chest radiograph shows a right lower lobe infiltrate. Which aspect of this patient's presentation is consistent with systemic inflammatory response syndrome? Blood pressure Heart rate Infiltrate on chest radiograph White blood cell count
Correct Answer ( B ) Explanation: Systemic inflammatory response syndrome (SIRS) is a state of systemic inflammation related to cytokine storm. Sepsis, pancreatitis, burns, trauma, and a number of other conditions can cause it. SIRS is defined by meeting two or more of the following criteria:
A 4-year-old girl presents to the office with lymphadenitis of several left cervical lymph nodes. An erythematous papule is noted on the left hand. What is the treatment of choice? Amoxicillin-clavulanate Azithromycin Clindamycin Glucocorticoids
Correct Answer ( B ) Explanation: The above patient has a classic presentation of Cat Scratch disease caused by Bartonella henselae. Inoculation of Bartonella results from a scratch by a kitten or cat or via a flea bite. The scratch or bite often results in a vesicle, which classically transforms into an erythematous papule. The lymphadenitis caused by Bartonella may develop anywhere between five days and two months after inoculation, but the papule can often still be located on the extremity distal to the lymphadenitis. The most commonly affected lymph nodes are in the axillary region, followed by the cervical region. Lymphadenopathy is localized in 2/3 of patients but may involve multiple anatomic regions in 1/3 of patients. Generalized lymphadenopathy is rare. The treatment of choice for Cat Scratch disease is five days of azithromycin. However, most Cat Scratch disease will resolve in 1-4 months if untreated.
A 17-year-old boy is concerned that he contracted a sexually transmitted infection from an episode of unprotected sexual intercourse during a trip to South Africa. Symptoms began with a very painful papule on his penis. The papule gradually ulcerated, and its edges became irregular. One week later, he developed painful right-sided inguinal adenopathy. Which empirical antibiotic is most likely to treat his infection? Acyclovir Azithromycin Benzathine penicillin G Trimethoprim-sulfamethoxazole
Correct Answer ( B ) Explanation: The patient has signs and symptoms of chancroid, a sexually transmitted infection caused by Haemophilus ducreyi. The infection is most common in developing and third world countries. Following an incubation period of 3-10 days, infected patients develop a painful genital papule or pustule, which then ulcerates to leave a ragged edge surrounding a necrotic center. Within one to two weeks, approximately half of affected patients develop tender, unilateral inguinal adenopathy, which may suppurate and form a fistula to the skin. Haemophilus ducreyi can be isolated from a swab of the ulcer or an aspirate of a fluctuant or draining node. Treatment options include azithromycin, erythromycin, ceftriaxone, or ciprofloxacin and, if possible, incision and drainage of suppurative lymph nodes. Benzathine penicillin G (C) treats early syphilis, which is characterized by a chancre, a painless papule with a shallow central ulceration. Trimethoprim-sulfamethoxazole (D) is appropriate treatment for granuloma inguinale, a sexually transmitted infection that is caused by Klebsiella granulomatis. The painless genital ulcer of granuloma inguinale has a rolled, distinct border with a beefy red, clean base, and ulcer biopsy contains classic Donovan bodies. Granuloma inguinale is more common in India and New Guinea.
An 18-year-old man presents with penile discharge after unprotected sex. A urine GC/Chlamydia test is ordered. Which of the following is an appropriate treatment regimen? Ceftriaxone 125 mg IM X 1 and azithromycin 1,000 mg PO X 1 Ceftriaxone 250 mg IM X 1 and azithromycin 1,000 mg PO X 1 Ciprofloxacin 500 mg BID X 7 days and azithromycin 1 000 mg PO X 1 Wait for the test results in order to tailor treatment
Correct Answer ( B ) Explanation: The patient has urethritis, which is likely caused by either Chlamydia trachomatis or Neisseria gonorrhea. Chlamydial infection and gonorrhea, the 2 most common nonulcerative sexually transmitted infections, also can cause vaginal discharge, especially in the setting of mucopurulent cervicitis, and both tend to cause urethral discharge in men. These 2 infections commonly occur concurrently, and clinical manifestations are clinically indistinguishable. Thus they should be simultaneously treated in all patients. Ceftriaxone 250 mg IM will treat the vast majority of N. gonorrhea strains and azithromycin 1,000 mg PO will treat C. trachomatis.
A 10-year-old boy presents with increased lethargy and vomiting. Mom states the patient has had 3 days of cough, rhinorrhea, sore throat, and fever. The nanny has been giving the patient an appropriate dose of over-the-counter cold medicine. The physical exam is remarkable for lethargy, mild icterus, and hepatomegaly. Laboratory results are remarkable for markedly elevated AST and ALT. Which medication is most likely responsible for this patient's presentation? Acetaminophen Aspirin Guaifenesin Ibuprofen
Correct Answer ( B ) Explanation: The patient's presentation is consistent with Reye's syndrome. Reye's syndrome is an uncommon, rapidly progressive, noninflammatory encephalopathy associated with altered mental status, cerebral edema, and hepatic dysfunction. Clinically, patients present with a respiratory or gastrointestinal prodrome followed by an encephalopathic picture marked by behavioral changes and deteriorating level of consciousness. It is a multisystem disease, but the mechanism of injury is not fully elucidated. Salicylate ingestion (aspirin) during a viral illness, particularly with chicken pox or influenza, is associated with the condition.
A 16-year-old boy comes to the clinic complaining of a change in mental status. He had a 2 cm painless genital ulcer that resolved on its own about one year ago. Screening tests reveal a positive rapid plasma reagin (RPR). Which of the following most likely represents the appropriate treatment regimen? Send a CSF VDRL and start benzathine penicillin (Bicillin L-A) 2.4 million units IM Send a CSF VDRL and start benzyl penicillin (penicillin G) 4 million units IV Send an FTA-ABS and start benzathine penicillin (Bicillin L-A) 2.4 million units IM Send an FTA-ABS and start benzylpenicillin (penicillin G) 4 million units IV
Correct Answer ( B ) Explanation: The various manifestations of syphilis are time dependent. Syphilis is classified as primary, secondary, and tertiary. Tertiary syphilis comprises three types: neurosyphilis, cardiovascular syphilis, and late benign syphilis (gummatous). The patient in this scenario is suspected of having neurosyphilis (based on his history of primary syphilis), given his positive RPR and altered mental status. Other symptoms of neurosyphilis include personality changes, bladder incontinence, headache, hearing loss, and blurred vision. RPR is a screening test; a CSF-VDRL should be sent to confirm the diagnosis. CSF pleocytosis is common prior to initiation of treatment, and serial LPs should be performed after treatment is completed to confirm cure. Adequate treatment of neurosyphilis is based largely on achieving treponemicidal levels of penicillin in the CSF. Treponema pallidum is highly susceptible to penicillin, which is the drug of choice for all stages of syphilis. Serum levels of penicillin should be maintained for many days because treponemes divide slowly in early syphilis and penicillin acts only on dividing cells. Therefore, treatment is with intravenous benzylpenicillin (penicillin G) 3-4 million units every four hours continuously for 10-14 days.
Rapid Review Influenza
Influenza Patient will be complaining of sudden onset of fever, headache, cough, myalgia, sore throat, fatigue Diagnosis is made clinically. Can be confirmed with reverse transcription-polymerase chain reaction (RT-PCR) or viral culture Treatment is mainly supportive or oseltamivir for high-risk patients Comments: Most common cause of viral pneumonia In adults
A 12-month-old boy is brought to his pediatrician's office for a rash. He had been running a fever (up to 103°F) for the previous three days. When the fever stopped, he developed this rash. He has received all recommended vaccinations. On exam, the child appears well and is afebrile. There is a maculopapular, nonpruritic rash covering his entire upper torso and head as shown above. Which of the following is the most likely diagnosis? Erythma infectiosum Roseola Rubella Rubeola
Correct Answer ( B ) Explanation: This child most likely has roseola. Roseola infantum, or sixth disease, is caused by the human herpesvirus 6. Roseola is most commonly seen in children < 2 years of age and occurs equally in boys and girls. Roseola transmission, in most cases, is sporadic. However, horizontal transmission has been reported. Patients with roseola classically present with an abrupt onset of high fever. After three to four days, rapid defervescence occurs and a blanching, nonpruritic macular or maculopapular rash develops. The rash typically starts on the neck and trunk and spreads peripherally. Patients generally do not experience upper respiratory symptoms. A few patients may develop febrile seizures. In patients with a classic roseola, laboratory studies are generally not indicated. Laboratory findings may include mild lymphocytosis and thrombocytopenia. Immunocompromised patients or patients with atypical presentations may warrant virologic studies. Roseola is self-limited in most cases and treatment is supportive. Acetaminophen can be useful to control fever. The rash resolves within two days without treatment. Complications are usually rare, but can include aseptic meningitis, encephalitis, and thrombocytopenic purpura. Rubella (B) is a vaccine-preventable exanthematous disease. The rubella rash typically starts on the face and spreads downward. Rubella is generally considered benign in children, but has teratogenic effects when mothers contract rubella during pregnancy. Rubeola (C), or measles, is distinguished by a prodrome of cough, coryza, Koplik spots, and a rash that begins on the face and spreads downward. Rubeola is seen in children who are unimmunized or under immunized.
A 12-year-old boy presents with high fever, muscle and joint aches, and headache for two days. He states he just got back from a camping trip in North Carolina. His exam is unremarkable. Labs are normal except for platelets of 95,000 and serum sodium of 128. Which of the following is the most appropriate next step in management? Obtain a Babesia microti DNA PCR and administer atovaquone and azithromycin Obtain a Rickettsia rickettsii immunofluorescence assay and administer doxycycline Send Lyme disease titers and administer amoxicillin Supportive care
Correct Answer ( B ) Explanation: This patient is suffering from early Rocky Mountain spotted fever (RMSF) from Rickettsia rickettsii. RMSF is a tick-borne illness which is endemic to North, South, and Central America. Although RMSF cases have been reported throughout most of the contiguous United States, five states (North Carolina, Oklahoma, Arkansas, Tennessee, and Missouri) account for over 60% of all cases. Clinically, RMSF is characterized by high fevers, arthralgias, myalgias, and a petechial rash, which begins on the ankles and wrists and spreads centrally. Early in the disease, there is often no rash and some patients with confirmed RMSF never develop a rash. Thus, early RMSF presents similar to a non-specific viral illness. The clinician may be steered towards the diagnosis of a RMSF by the presence of thrombocytopenia and hyponatremia. R. rickettsii is an obligate intracellular bacteria transmitted to humans by the American dog tick (Dermacentor variabilis) and the Rocky Mountain wood tick (Dermacentor andersoni). RMSF can progress to involve the cardiopulmonary system (myocarditis, AV blocks, dysrhythmias, interstitial pneumonitis, pulmonary edema, etc.), nervous system (encephalomyelitis, meningitis, cerebral thrombovasculitis, etc.) and cutaneous (vasculitis, ecchymosis, and ulcerations). Ricketsial antibodies can be performed but indirect immunofluorescence assay (IFA) is the standard test for diagnosis as it has a high sensitivity (95%). Treatment is most effective when started early in the course of disease. Doxycycline 100 mg twice a day for 7-10 days is the most common therapy but chloramphenicol can be substituted in those with a severe reaction to tetracycline antibiotics. Babesiosis (A) should always be on the differential diagnosis with RMSF and can cause thrombocytopenia but does not cause hyponatremia.
A 34-year-old man presents with a deep laceration to the left leg after falling off a motorcycle. The wound is contaminated with rocks and dirt. He states that he has not received a tetanus shot since completing vaccinations as a child. After irrigation and repair, which of the following should be administered? No tetanus prophylaxis needed Tdap Tdap and Tetanus immune globulin Tetanus immune globulin
Correct Answer ( B ) Explanation: This patient presents with a dirty wound and no tetanus booster in the last 5 years and thus requires a tetanus booster during this presentation. Tetanus is a toxin-mediated disease that is characterized by uncontrollable skeletal muscle spasms. It can cause hypoventilation, hypoxia and death if the toxin affects the muscles of respiration. Tetanus is a relatively rare disease particularly in developed countries where vaccination programs have been successful. Primary immunization confers protective antibodies to nearly 100% of patients. Immunity wanes between 5 and 10 years after completion of the initial vaccination series and so patients should have a booster shot every 10 years. It typically affects patients who have sustained a deep, penetrating wound. In adult patients with a history of a primary series in the past, any wound that is not a clean/minor wound should be given a tetanus shot (Tdap) if their last booster was >5 years ago. If the patient has a history of not completing a primary series, they should be given a Tdap regardless of the wound depth or size.
A 17-year-old boy from New Jersey presents with a 3-day history of rash and a 1-day history of facial droop. He also complains of a headache. The images above represent the physical examination findings. In addition you note mild nuchal rigidity. A non-contrast head CT is performed and is normal. Which of the following is the next best step for this patient? Acyclovir and corticosteroids Lumbar puncture MRI brain Serologic testing for Lyme disease
Correct Answer ( B ) Explanation: This patient presents with a rash consistent with erythema migrans and facial nerve palsy indicating a likely early disseminated Lyme disease infection and should receive a lumbar puncture to further assess for neurologic disease. Lyme disease is primarily transmitted via the Ixodes scapularis tick. The disease manifests with a number of phases beginning with early Lyme. Early Lyme typically manifests (90% of cases) with the classic erythema migrans rash. The rash begins at the site of the bite and progresses outwards. It typically exhibits central clearing. At this time, patients may also experience non-specific flu-like symptoms. Acute disseminated infection occurs after hematogenous spread of the spirochete and can result in neurologic, cardiac (heart block), arthritis, and ophthalmic manifestations. The most common neurologic manifestation is meningoencephalitis with superimposed cranial neuropathies. CNS Lyme is treated with ceftriaxone and so it is important to obtain a lumbar puncture in patients with neurologic manifestations (eg, headache, nuchal rigidity, vomiting, visual changes, confusion) to rule this in or out. Lumbar puncture will show lymphocytic pleocytosis with a moderately elevated protein level. PCR and cultures can be sent for Borrelia burgdorferi as well.
What is the causative agent for the above rash? Coxsackie virus Herpes simplex virus Smallpox virus Staphylococcus aureus
Correct Answer ( B ) Explanation: This patient presents with painful grouped vesicles on an erythematous base consistent with a herpes simplex virus (HSV) infection. HSV is a common viral infection affecting a considerable portion of adults. There are two variants of HSV that cause human infection. HSV-1 typically affects nongenital sites and HSV-2 typically affects the genital area and is transmitted by sexual contact. HSV lesions typically present as painful, grouped vesicles that are localized in a nondermatomal distribution. Oral lesions are the most common site of HSV-1 infections. In addition to affecting the lips, they can also cause ulcerations to the gingiva, tongue and mouth. Outbreaks can be accompanied by fever and lymphadenopathy. A first episode of HSV can be treated with acyclovir, famciclovir or valacyclovir for 7-10 days. These agents accelerate healing and reduce the length of viral shedding.
Which of the following is an absolute contraindication to the diphtheria vaccine? Family history of sudden infant death syndrome Moderate or severe illness Previous anaphylaxis to DTaP Previous seizure within three days of last DTaP dose
Correct Answer ( C ) Explanation: The routine childhood immunization schedule in the United States includes vaccination against diphtheria, tetanus and pertussis. There has been a dramatic decrease in the incidence of diphtheria since the initiation of the vaccine in the 1940's. Corynebacterium diphtheriae causes acute cutaneous or respiratory illness and can be fatal. Mortality is higher in children under the age of five. The recommended schedule is five doses of the diphtheria, tetanus and pertussis (DTaP) vaccine at ages 2 months, 4 months, 6 months, 15-18 months and 4-6 years. The tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (TDaP) is used as a single booster dose for adolescents or adults. Absolute contraindications to the DTaP vaccine include previous anaphylaxis to DTaP, anaphylactic reactions to latex, and progressive neurologic disorder and encephalopathy within seven days of a previous dose of DTaP without identifiable cause.
A 51-year-old man presents to the ED with foot pain. Vital signs are BP 105/80, HR 122, RR 18, and T 38.4°C. Finger stick blood glucose is 445 mg/dL. You obtain a radiograph of the foot as seen above. Which of the following is the most appropriate next step in management? Administer 2 L of normal saline and 10 units of regular insulin Administer parenteral antibiotics and perform an incision and drainage Begin antibiotics and consult general surgery Send ESR, CRP, and consult orthopedics
Correct Answer ( C ) Explanation: The radiograph reveals gas in the soft tissue of the foot. In conjunction with the patient's clinical presentation, the diagnosis is necrotizing fasciitis. Management includes surgical debridement by a surgeon and parenteral antibiotics. Supportive measures with intravenous fluids and possible vasopressor support may be indicated. Necrotizing fasciitis is more common in men than in women and frequently involves the lower extremities. There are 2 types of necrotizing fasciitis: Type 1 is polymicrobial and involves nongroup A streptococci plus anaerobes and usually occurs on the abdomen and perineum; Type 2 is due to group A beta-hemolytic streptococci, and the infection usually involves the extremities. Clinical findings include tenderness, edema, and erythema at the site of infection. Fever is usually present. Numbness or deep pain out of proportion to the exam is classic. The presentation can be deceiving because in many cases, the skin will appear normal, but the patient will complain of pain. By days 2 to 4, necrotic patches and bullae appear. At this point, gas may appear on the radiograph, but the absence of gas does not exclude the diagnosis. Due to the rapid spread of the infection, patients need to undergo immediate surgical debridement to remove the dead tissue. Broad-spectrum antibiotics and intravenous fluids should also be administered.
A patient with AIDS presents with fever, severe headache, and positive Kernig's sign. CSF findings reveal lymphocytosis and increased protein levels. India ink staining reveals encapsulated yeast forms. Which of the following is the most likely pathogen? Borrelia burgdorferi Candida albicans Cryptococcus neoformans Neisseria meningitidis
Correct Answer ( C ) Explanation: Although all of the above pathogens can cause meningitis in a patient with AIDS, Cryptococcus neoformans has the following spinal fluid findings, including increased opening pressure, variable pleocytosis, increased protein, and decreased glucose. Gram stain of the cerebrospinal fluid usually reveals budding, encapsulated fungal cells. Prior to waiting on Gram-stain results, the CSF can be sent for detection of the cryptococcal antigen (highest sensitivity in AIDS patients). Detecting a serum cryptococcal antigen also aids in the diagnosis. Treatment of cryptococcal meningitis involves antifungal therapy such as amphotericin B and flucytosine, followed by fluconazole suppression until adequate immune reconstitution, or if this does not occur, indefinitely.
Which of the following is the most common physical exam finding in a patient with botulism? Fever Loss of consciousness Muscle weakness Tachycardia
Correct Answer ( C ) Explanation: Botulism is a rare but life-threatening condition caused by the Clostridium botulinum neurotoxin. In the United States, the most common type of botulism is infant botulism, followed by foodborne and wound botulism. Botulism classically presents with an acute onset of bilateral cranial neuropathies and symmetric descending muscle weakness. A high degree of clinical suspicion based on history and physical exam is critical in the diagnosis. Patients with clinical signs and symptoms of botulism along with a history that is suspicious for the disease should be hospitalized immediately. Respiratory failure is the most common cause of death and therefore respiratory function should be monitored closely.
A 3-month-old infant is transferred from an outside hospital with three days of cough and congestion. Today, she developed increased work of breathing. Exam was significant for intercostal retractions, diffuse soft expiratory wheezing, and coarse crackles. A chest radiograph shows bilateral hyperinflation and areas of atelectasis with volume loss. What is the most likely diagnosis? Bacterial pneumonia Status asthmaticus Viral bronchiolitis Viral pneumonia
Correct Answer ( C ) Explanation: Bronchiolitis is a clinical syndrome resulting from inflammation of the bronchioles. It is extremely common during the fall and winter, and it occurs almost exclusively in infants and children < 2 years of age. The most common viral etiology is Respiratory Syncytial Virus (RSV), but it may also be caused by parainfluenza, rhinovirus, human metapneumovirus, influenza, human bocavirus, and adenovirus. Symptoms typically begin with upper respiratory congestion and progress to cough and other lower respiratory symptoms, such as chest congestion, tachypnea, and increased work of breathing. Bronchiolitis is a self-limited process, but the associated cough may last up to four weeks. Some children will require hospitalization for supplemental oxygen, high flow nasal cannula or mechanical ventilation, or intravenous hydration. Infants and children without respiratory distress, hypoxemia, or dehydration may be treated in the outpatient setting with management of secretions and monitoring of fluid status.
23-year-old man presents with two days of "rice water" diarrhea after a recent trip to India. What is the appropriate pharmacologic treatment for his condition? Amoxicillin Cephalexin Ciprofloxacin Piperacillin
Correct Answer ( C ) Explanation: Cholera is an acute form of diarrhea caused by the gram-negative bacterium Vibrio cholerae, which is transmitted via the fecal oral route. It is endemic in certain regions, such as Asia and Africa, and cases in the U.S. are most often imported from travelers such as in this patient's case. Isolation of V. cholerae in a stool sample establishes a definitive diagnosis, but providers may make a presumptive diagnosis of cholera based on its clinical presentation. The diarrhea produced by cholera is frequently described as having the consistency of rice water, and may be profuse, leading to dehydration. Administration of appropriate rehydration, therefore, is the cornerstone of treatment. However, antibiotic treatment has been shown to reduce the duration and quantity of diarrhea, as well as decrease the shedding of V. cholerae. Appropriate antibiotic selection for cholera include macrolides, tetracyclines, and fluoroquinolone, such as ciprofloxacin
You suspect a 35-year-old man has epiglottitis with impending airway compromise. Which of the following is the best method for confirming the diagnosis? Computed tomography of the neck Frontal cervical soft tissue radiograph Indirect laryngoscopy Lateral cervical soft tissue radiograph
Correct Answer ( C ) Explanation: Direct and indirect laryngoscopy both enable visualization of the airway structures, including the epiglottitis. Direct laryngoscopy refers to the use of a laryngoscope to elevate the tongue and supraglottic structures with the patient in a supine position. Indirect laryngoscopy refers to the visualization of the vocal cords without a direct line of sight, using instruments such as a nasopharyngeal laryngoscope. With both methods, however, care should be taken to ensure that manipulation does not lead to laryngospasm and airway obstruction. Prior to any attempts at airway visualization, humidified oxygen should be administered (the data do not support administration of steroids or racemic epi), and emergent intubation along with surgical airway equipment should be gathered. Lateral cervical soft tissue radiograph (D) has a sensitivity of up to 90% for the diagnosis of epiglottitis. However, a normal-appearing radiograph does not exclude the diagnosis of epiglottitis. Patients with suspected epiglottitis and a normal radiograph should undergo laryngoscopy.
Which of the following sexually transmitted infections has a high rate of cotransmission with HIV infection? Gardnerella vaginalis Neisseria gonorrhoeae Treponema pallidum Trichomonas vaginalis
Correct Answer ( C ) Explanation: Disorders characterized by genital ulcers (syphilis, herpes, chancroid, lymphogranuloma venereum, granuloma inguinale) have high rates of HIV cotransmission. Treponema pallidum is the causative agent of syphilis and is associated with a painless ulcer during the initial stage of infection (primary syphilis). Ulcers typically appear 3 to 6 weeks after exposure
What key clinical finding differentiates erysipelas from cellulitis? Induration Peau d'orange appearance Sharp demarcation from uninvolved skin Systemic symptoms
Correct Answer ( C ) Explanation: Erysipelas is a superficial skin infection involving the upper dermis with prominent lymphatic involvement. Beta-hemolytic streptococci usually cause it. Erysipelas is characterized by an erythematous area of skin that becomes indurated with raised borders distinctly demarcated from the surrounding normal skin. The skin may also exhibit a "peau d'orange" appearance. A classical manifestation is malar involvement with a "butterfly" pattern over the face. Because erysipelas involves the upper dermis and superficial lymphatics, whereas cellulitis involves the deeper dermis and subcutaneous fat, erysipelas can spread to pinna of the ear, whereas cellulitis cannot.
Which of the following is true regarding botulism? Foodborne botulism develops 10-14 days following toxin ingestion Foodborne botulism is caused by ingestion of a heat-stable toxin (type A) Infantile botulism is the most common form Intestinal colonization is common in foodborne botulism
Correct Answer ( C ) Explanation: First described in the mid-1970s, infantile botulism is now the most common form of botulism in the United States. Children typically present with poor feeding, decreased suckling, loss of facial expression, constipation, and noticeable neck and peripheral weakness—a constellation of symptoms known as "floppy baby syndrome." It occurs in children younger than 12 months of age, with a peak incidence at three months. It has been associated with ingestion of honey, corn syrup, and vacuum or environmental dust. It is caused by the ingestion and subsequent intestinal colonization of Clostridium botulinum spores in the intestinal tract.
A 21-year-old nurse presents after a needle stick from a needle that was uncapped and sticking out of the sharps container. Which of the following is most accurate in terms of HIV prophylaxis? Antiretroviral medications are taken for two weeks Post-exposure prophylaxis decreases rates of seroconversion by 25% Post-exposure prophylaxis started within two hours improves transmission prevention The window for initiation of treatment is 96 hours
Correct Answer ( C ) Explanation: HIV prophylaxis is indicated for a needle stick injury where there is any concern about the possibility of transmission of HIV. The risk of acquiring HIV from an infected needle stick is on average 0.3%. Other factors that play into the likelihood of transmission include the stage of illness of the source patient, depth of injury and whether blood was visible on the device. The most effective treatment is when the first dose of medication is administered within two hours of exposure. Exposed persons are started on antiretroviral medications that prevent HIV from replicating to a degree that is capable of causing seroconversion. The CDC recommends a two or three drug regimen based on the risk of exposure. Some states have their own guidelines established about particular medication.
Two weeks after returning from a spelunking trip in Illinois, a previously healthy 25-year-old man presents with a flu-like illness. Which of the following is the most likely causative organism? Borrelia burgdorferi Epstein-Barr virus Histoplasma capsulatum Rickettsia rickettsia
Correct Answer ( C ) Explanation: Histoplasma capsulatum is the fungus that causes histoplasmosis. Commonly found in the Ohio and Mississippi river valleys, Histoplasma capsulatum grows in soil enriched with bat or bird droppings. High-risk activities in endemic areas include spelunking, cleaning of chicken coops, excavation, cutting dead trees, and remodeling or demolition of old houses. Inhalation of Histoplasma capsulatum causes infection with a clinical spectrum ranging from asymptomatic to life threatening. Patients present with symptoms similar to the flu including fever, sweats, headache, cough, dyspnea, chest pain, anorexia and myalgia. Treatment recommendations are based on the type of histoplasmosis
Which of the following is the most likely etiologic agent of the rash pictured above? Coxsackievirus Group A Human herpes virus 6 Parvovirus B19 Rubella virus
Correct Answer ( C ) Explanation: The most commonly recognized manifestation of parvovirus B19 infection is erythema infectiosum, also known as fifth disease. This is a benign, self-limited childhood exanthem. After a two-week incubation period, patients often develop very mild URI-type symptoms followed in three to four days by the classic "slapped-cheek" rash that appears suddenly. It is believed that the development of the rash corresponds to the onset of immune response and sudden production of anti-B19 antibodies. Parvovirus B19 has also been associated with the development of severe disease, including a symmetric polyarthropathy, myocarditis, and pericarditis. Prior theories also connected Parvovirus B19 to kidney disease, specifically focal segmental glomerulonephritis; however, this has recently been found to be coincidence rather than correlation or cause. Primary infection in patients with sickle cell disease may lead to an aplastic crisis due to disruption of hematopoiesis. Nonimmune women who become infected during pregnancy are at risk of congenital infection that may lead to hydrops fetalis and fetal loss.
Which of the following is consistent with a diagnosis of infectious mononucleosis? Anterior cervical lymphadenopathy Grayish-white pseudomembrane on the tonsils, uvula, and soft palate Maculopapular rash following treatment with amoxicillin Vesicular lesions and ulcerations on the soft palate
Correct Answer ( C ) Explanation: Infectious mononucleosis is caused by the Epstein-Barr virus. While young children with the disease typically have minimal, if any, symptoms related to the infection, adolescents and young adults usually have a more pronounced course. It is uncommonly seen in adults as most are immune due to a previous exposure. Patients may have a prodrome of low-grade fever, headache, and malaise. There is pharyngeal erythema and tonsillar exudates that may appear white, gray-green, or necrotic. Palatal petechiae can also be seen, but may be present in streptococcal pharyngitis as well. Severe fatigue is common and often the symptom that persists the longest. The lymphadenopathy is usually mildly tender, symmetric and involves the posterior cervical chain. Hepatosplenomegaly can be noted on examination. A generalized maculopapular rash almost always occurs following administration of amoxicillin or ampicillin although the mechanism of this is unclear. Diagnosis is made based on history and physical and can be confirmed with a positive heterophile antibody test (monospot test). Treatment is supportive. Symptoms generally resolve in 1-3 weeks although the fatigue may persist for months. Patients should refrain from contact sports for four weeks post-infection. Vesicular lesions and ulcerations on the soft palate (D) are a sign of herpes stomatitis
A 16-year-old male presents with a sore throat, adenopathy, and fatigue. He has no evidence of airway compromise. A heterophil antibody test is positive. Appropriate management includes which one of the following? A corticosteroid An antiviral agent Avoidance of contact sports Bed rest
Correct Answer ( C ) Explanation: Infectious mononucleosis presents most commonly with a sore throat, fatigue, myalgias, and lymphadenopathy, and is most prevalent between 10 and 30 years of age. Both an atypical lymphocytosis and a positive heterophil antibody test support the diagnosis, although false-negative heterophile testing is common early in the disease course. The cornerstone of treatment for mononucleosis is supportive, including hydration, NSAIDs, and throat sprays or lozenges. It is also associated with an enlarged spleen. Therefore, patients should be advised to avoid contact- or collision-type activities for 3-4 weeks because of the increased risk of rupture and should avoid physical activity for approximately 6 weeks. The mainstay of treatment for infectious mononucleosis is good supportive care, including adequate hydration, nonsteroidal anti-inflammatory drugs or acetaminophen for fever and myalgias.
A six-year-old boy presents to his pediatrician's office with a 12-hour history of headache, stiff neck, fever to 104°F, and lethargy. A complete blood count and differential, urinalysis, blood culture, and electrolytes are ordered. While under observation, awaiting the results of the blood tests, in the doctor's office, the boy begins vomiting and develops a petechial rash from head to feet followed rapidly by the formation of necrotizing purpura. Two hours later, while awaiting transport to a children's hospital, he develops shock, has a cardiac arrest, and dies. What is the most likely diagnosis, from the list below? Idiopathic thrombocytopenia Leukemia Meningococcal meningitis Viral encephalitis
Correct Answer ( C ) Explanation: Meningococcal meningitis caused by Neisseria meningitides is one of the most feared and rapidly fulminant infectious diseases. Although meningococcal sepsis can follow an even more rapid course than meningococcal meningitis, the headache and stiff neck are consistent with meningeal involvement. The rapid course in this patient, with a marked fever rapid development of the petechial rash with progression to necrotizing purpura are classic for meningococcal sepsis, with or without meningitis. The skin lesions are a manifestation of cutaneous vasculitis from which the organism can be demonstrated microscopically or on culture. The shock, cardiac arrest, and death are a manifestation of endotoxemia associated with the bacterial cell wall of these Gram-negative organisms.
What is the most common sexually transmitted infection in the United States? Chlamydia Gonorrhea Human papillomavirus Syphilis
Correct Answer ( C ) Explanation: More than 50% of sexually active individuals will contract human papillomavirus (HPV) at some point in their lives. There are over 100 types of HPV, many of which are asymptomatic and unrecognized. Two high-risk types of the virus, HPV 16 and 18, are known to cause cervical and anogenital cancers in men and women. HPV 6 and 11 are low-risk types that cause genital warts. Two HPV vaccines are available and are recommended for both men and women aged 11-12 years old. HPV2, Cervarix® for women only and HPV4, Gardasil® for both men and women. The vaccinations can also be given to females ages 13-26 years and males ages 13-21 years who were not vaccinated earlier.
A 19-year-old man is working in Chicago for the Mercantile Exchange and develops mildly painful swelling over his parotid glands. On presentation to his primary care physician, a week later, he has a low-grade fever, earache, mild headache, and mild testicular pain. He denies sexual activity, and a few of his coworkers have similar symptoms. On physical exam, his physician finds the bilateral parotid pain with boggy edematous parotid tissue, minimal adenopathy, mild presternal edema, moderate abdominal pain over the pancreas, and mild testicular pain. Which one of the following is the most likely diagnosis in this young man? Atypical mycobacterial infection Epstein-Barr virus infection Mumps virus infection Parainfluenza virus infection
Correct Answer ( C ) Explanation: Mumps virus infection, in an unimmunized individual or in an individual who has not had a protective response to the vaccine, presents generally with acute parotid gland inflammation and swelling, and the pain often radiates up to the ear. It is a systemic disease with low-grade fever, involving other glandular tissue, including the pancreas and testicles. It can also be associated with mild CNS involvement.
A 25-year old man presents to your office after recently being diagnosed with HIV infection at the health department. You obtain blood work and note that his CD4+ count is 180. This patient should receive prophylaxis against which one of the following opportunistic infections? Histoplasma capsulatum Mycobacterium avium-intracellulare complex Pneumocystis jirovecci Toxoplasma gondii
Correct Answer ( C ) Explanation: Patients with HIV infection and severe immunodeficiency are at risk for certain opportunistic infections. Susceptibility to opportunistic infections can be measured by CD4+ T lymphocyte counts. Patients with a CD4+ count < 200 should receive trimethoprim/sulfamethoxazole for prevention of Pneumocystis jirovecci pneumonia (PCP pneumonia). Pneumocystis jiroveci pneumonia remains relatively common in patients with HIV infection, and may be the presenting manifestation of HIV in patients who have not yet been diagnosed. Patients with P. jiroveci pneumonia classically present with fever, progressive exertional dyspnea, and nonproductive cough. Although there are a wide variety of radiologic findings, chest radiography typically shows bilateral interstitial infiltrates. Prophylaxis with itraconazole may be considered for Histoplasma capsulatum (A) in patients with CD4+ T-lymphocyte counts less than 100 who are at especially high risk because of occupational exposure or who live in a community with a hyperendemic rate of histoplasmosis (10 or more cases per 100 patient-years).
In patients with a history of HIV infection and a CD4 count less than 200, which of the following opportunistic infections is trimethoprim-sulfamethoxazole (TMP-SMX) administered for prophylaxis? Coccidioidomycosis Disseminated mycobacterium avium complex disease Pneumocystis pneumonia Streptococcus pneumoniae
Correct Answer ( C ) Explanation: Pneumocystis jiroveci (formerly called Pneumocystis carinii) is an opportunistic pathogen in patients with HIV/AIDS. It causes a rapidly progressive fungal pneumonia characterized by severe hypoxia. In individuals with HIV infection, chemoprophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is recommended when CD4 counts below 200 cells or there is a history of oropharyngeal candidiasis to help prevent PCP pneumonia. One double strength tablet daily is the recommended regimen, but one single strength tablet is also effective and better tolerated.
A 14-year-old boy presents to the Emergency Department for a rash. He reports the abrupt onset of fever, headache, and myalgias three days ago. This morning, he developed a blanching, red, macular rash on his wrists and palms that now involves his extremities and trunk. What is the most likely cause of his symptoms? Measles virus Neisseria meningitidis Rickettsia rickettsii Staphylococcus aureus
Correct Answer ( C ) Explanation: Rocky Mountain spotted fever (RMSF) is a febrile, tick-borne illness caused by Rickettsia rickettsii. Patients present with abrupt onset of fever, headache, myalgias, and nausea followed three to five days later with a blanching, macular rash that initially is found on the wrists and ankles before spreading centripetally. The rash later becomes petechial. Despite its name, RMSF is relatively rare in the Rocky Mountain states and is found primarily in the southeastern United States. Carried mostly by the American dog tick (Dermacentor variabilis) and the Mountain wood tick (Dermacentor andersoni), R. rickettsii is an obligate intracellular bacteria that damages endothelial cells. This in turn starts a cascade of reactions that result in widespread vascular lesions that manifest as the clinical features of the disease. Without treatment, mortality is near 25%. Management includes supportive care and doxycycline. Neisseria meningitidis (B) can also cause a fever, headache, and rash. However, the rash associated with N. meningitidis typically spares the palms and soles. Staphylococcus aureus (D) can cause toxic shock syndrome which is characterized by fever, hypotension, and a diffuse erythematous macular rash that later desquamates.
An eight-year-old girl is seen in your office with abdominal pain, bloody diarrhea, and weight loss for the past few weeks. Her family just returned from Africa. You obtain a stool sample and find Schistosome eggs. Which of the following medications is the treatment of choice for this infection? Albendazole Ivermectin Praziquantel Prednisone
Correct Answer ( C ) Explanation: Schistosoma organisms infect humans via contaminated water in endemic areas. The parasite is carried by snails and is capable of penetrating intact human skin. There are many different species of Schistosome. Children with Schistosoma mansoni present with intestinal symptoms such as abdominal pain and bloody diarrhea. Once in the bloodstream S. mansoni spread hematogenously to the inferior mesenteric veins. The diagnosis is made by microscopic stool examination for eggs. The treatment of choice is praziquantel 40 mg/kg/day twice daily for one day.
A 16-year-old male football player presents to the emergency room confused and in shock. There is no history of trauma, travel, preceding illness, or animal exposure. The young man appears pale, diaphoretic, and tachycardic, with a respiratory rate of 24 and a blood pressure of 95/55. Palpation of the slightly swollen right thigh is exquisitely painful, and there is slight erythema over that area. After aggressive fluid administration, an emergency MRI demonstrates a suppurative process involving the fascia of his right thigh. Which of the following is the most appropriate treatment at this time? Administer morphine for pain relief Obtain a CT scan with IV contrast of the right thigh Start intravenous vancomycin and clindamycin Start tetracycline orally
Correct Answer ( C ) Explanation: Start intravenous vancomycin and clindamycin. Streptococcal Toxic Shock Syndrome (Strep TSS), as is true for any disease process manifesting with shock, is a medical emergency. One or more pyrogenic exotoxins secreted by Streptococcus pyogenes (Group A Strep) when it invades host tissues, is responsible for the syndrome. A similar but not identical pyrogenic exotoxin is produced by Staphylococcus aureus and may present with a similar clinical picture. It is, therefore, prudent to start antibiotics that cover both Strep and Staph, such as vancomycin, as soon as possible after treatment for shock is instituted. It has furthermore been demonstrated that treatment of toxic shock syndromes with a beta-lactam antibiotic such as penicillin or ampicillin is clinically inferior to a ribosomally active antibiotic such as clindamycin. This is thought to reflect the ability of clindamycin to turn off toxin production by the invasive bacteria. In addition to antibiotics, these patients often require surgical consultation for possible debridement.
A 36-year-old man presents to the emergency department after accidentally puncturing his palm with a rusty nail. He has received two prior doses of a tetanus toxoid-containing vaccinations. Which of the following regimens should be given to this patient? No prophylaxis needed Tetanus immune globulin only Tetanus toxoid and tetanus immune globulin Tetanus toxoid only
Correct Answer ( C ) Explanation: Tetanus toxoid and tetanus immune globulin should both be given to a patient who sustains a dirty puncture wound and has received less than three doses of the tetanus vaccination in the past. Tetanus is a nervous system disorder caused by Clostridium tetani, an obligate anaerobe found in soil. When spores enter the body through openings of the skin, toxin is released causing muscle spasms and muscle rigidity. More than half of patients present with symptoms of trismus, or lockjaw. When tetanus is suspected, the patient's tetanus vaccination history must be revealed. If a patient presents with a clean and minor wound, a tetanus toxoid-containing vaccination such as the tetanus-diphtheria-acellular pertussis vaccine (Tdap) or tetanus-diphtheria vaccine (Td) is given only if a patient has gotten less than three doses of the vaccine in their lifetime or if their last dose of the vaccine was given over 10 years ago. For wounds contaminated with dirt, soil, feces, or saliva; puncture wounds; avulsions; or are a result of missiles, crushing, burns, or frostbite, they are considered to be at high risk for tetanus and therefore prophylaxis is warranted immediately after injury if indicated (> 5 years since last vaccine). In a patient with an unknown vaccination history or if they have had fewer than three doses of the vaccination in their past, they must receive the tetanus toxoid in either the Tdap or Td form and the tetanus immune globulin. Giving both ensures adequate protective levels against the toxin. Tetanus immune globulin only (B) is not an option in a patient who sustains a wound, whether it be clean or dirty. Tetanus immune globulin provides temporary immunity by directly providing an antitoxin to neutralize the free toxins produced by the bacterium. If this is administered, the tetanus toxoid should also be administered. Tetanus toxoid only (D) is only given if a patient has a clean, minor wound and has either never been vaccinated against tetanus or has had fewer than three injections, or if a patient has either a clean or dirty wound and has not received their last tetanus toxoid-containing vaccine dose within the last ten or five years, respectively.
Which of the following constitutes the Systemic Inflammatory Response Syndrome (SIRS) criteria? Heart rate > 80 and Respiratory Rate > 16 Heart rate > 90 Heart rate > 90 and temperature >100.4°F Temperature > 100.4°F and WBC > 10,000
Correct Answer ( C ) Explanation: The SIRS criteria is part of the sepsis syndrome spectrum of diseases. SIRS often represents the body's host response to an infection. Although research has found that SIRS criteria alone does not predict an increased mortality, it should prompt continued investigation for an underlying pathology. The presence of organ dysfunction and shock, however are significant predictors of adverse outcomes and should be fully addressed. Sepsis is the tenth most common cause of death in the US.
A 10-year-old boy is brought to the emergency room because of a headache. For the past three days, he has had a fever and a headache. Then, this morning his mother noted the presence of a rash. He denies vomiting, abdominal pain, neck pain, or coughing. Last week, he went hiking with his father although he denies any tick bite. On physical examination, temperature is 38.7℃, heart rate is 88 per minute, and respiratory rate is 23 per minute. There is a blanching erythematous rash with macules on the ankles and wrists. Which of the following is the most likely diagnosis? Leptospirosis Meningococcal meningitis Rocky Mountain spotted fever Thrombotic thrombocytopenic purpura
Correct Answer ( C ) Explanation: The boy has signs and symptoms that are suspicious for Rocky Mountain spotted fever (RMSF). RMSF is usually transmitted via tick bite. The principal vector of RMSF in the eastern and south central United States is Dermacentor variabilis. On the other hand, Dermacentor andersoni is the primary vector in the mountain states west of the Mississippi River. Infected patients become symptomatic two to 14 days after being bitten by an infected tick. Classic symptoms of RMSF include fever, headache, and rash in a person with a history of a tick bite. Rash occurs in approximately 88 percent to 90 percent of patients. The hallmark of RMSF is a blanching erythematous rash with macules that become petechial over time. The appearance of the rash usually begins on the ankles and wrists and spreads to the trunk. The rash that appears on the palms and soles is highly characteristic of RMSF, but usually occurs in later-stage disease. A presumptive diagnosis of RMSF is initially made based upon consistent clinical signs and symptoms in the appropriate epidemiologic setting. The clinical diagnosis must be confirmed through serologic testing or through the use of special stains on a skin biopsy Leptospirosis (A) generally presents with the abrupt onset of fever, rigors, myalgias, and headache, and conjunctival suffusion. The presentation of meningococcal meningitis (B) consists of the sudden onset of fever, nausea, vomiting, headache, decreased ability to concentrate, and myalgias in an otherwise healthy patient. The petechial rash appears as discrete lesions, most frequently on the trunk and lower portions of the body. Petechiae can coalesce into larger purpuric and ecchymotic lesions. Thrombotic thrombocytopenic purpura (D) usually presents with fatigue, dyspnea, petechiae, or other signs of bleeding.
A 14-year-old boy is brought by his mother to your clinic due to orange colored tears. Further questioning reveals that the boy was diagnosed with latent tuberculosis and was prescribed with an unrecalled antimycobacterial agent three weeks ago. Two days ago, the boy noted orange colored urine, tears and saliva. You suspect that this is an adverse effect of the drug previously prescribed. What is the mechanism of action of the drug? Binds irreversibly to the 30s subunit of ribosomes inhibiting protein synthesis Competitive antagonist of para-aminobenzoic acid which is needed for the bacterial synthesis of folic acid Inhibition of DNA-dependent RNA polymerase resulting in decreased RNA synthesis Involvement of the isoniazid gene that encodes the enoyl-acyl carrier protein reductase needed for the last step of the mycolic acid biosynthesis pathway of cell wall production
Correct Answer ( C ) Explanation: The boy is suffering from tuberculosis. There are five closely related mycobacteria in the Mycobacterium tuberculosis complex: M. tuberculosis, M. bovis, M. africanum, M. microti, and M. canetti. M. tuberculosis is the most important cause of tuberculosis disease in humans. The tubercle bacilli are non-spore-forming, nonmotile, pleomorphic, weakly Gram-positive curved rods 1-5 μm long, typically slender and slightly bent. Rifampin is active against M. tuberculosis, Mycobacterium leprae, M. kansasii, and Mycobacterium avium complex. Rifampin is an integral drug in standard combination treatment of active M. tuberculosis disease and can be used as an alternative to isoniazid (INH) in the treatment of latent tuberculosis infection in children who cannot tolerate INH. All rifamycins including rifampin can turn urine and other secretions (e.g., tears, saliva, stool, sputum) orange. The rifamycins inhibit the DNA-dependent RNA polymerase of mycobacteria, resulting in decreased RNA synthesis.
A 34-year old resident physician from Iowa presents for a health examination prior to hospital employment. His examination is unremarkable, but a chest radiograph shows bilateral lung fields with BB-sized calcifications and hilar adenopathy. A PPD skin test is negative. The findings in this patient are most likely a result of which of the following? Coccidioidomycosis Cryptococcosis Histoplasmosis Tuberculosis
Correct Answer ( C ) Explanation: The majority of people with normal immunity who develop histoplasmosis manifest an asymptomatic or clinically insignificant infection. The most common abnormality on chest radiograph is a solitary pulmonary calcification. Cavitation is rare, but hilar and mediastinal adenopathy is seen frequently. It is highly prevalent in the Midwestern United States and exposure to bird or bat excrement is a common cause. The spectrum of this illness ranges from asymptomatic infection to severe disseminated disease. Culture remains the gold standard for diagnosis but requires a lengthy incubation period. Fungal staining produces quicker results than culture but is less sensitive. Therapy is indicated in chronic or disseminated disease and severe, acute infection. Amphotericin B is the agent of choice in severe cases and itraconazole is effective in moderate disease. The chest radiographic findings in coccidiomycoses (A) can be normal or may progress from single or multiple areas of airspace consolidation to the formation of nodules or cavities. Clinical symptoms are similar to those found in histoplasmosis however, coccidiomycoses is generally seen in inhabitants of the southwestern United States. A patient with pulmonary cryptococcosis (B) may present with mild-to-moderate symptoms, including fever, malaise, cough with scant sputum, pleuritic pain, and hemoptysis. On chest radiography, cavitation and hilar lymphadenopathy are uncommon. Calcification and pulmonary fibrosis or stranding are usually absent. Patients with tuberculosis (D) will have a positive protein purified derivative (PPD) skin test unless they are severely immunocompromised. Chest radiographs may show a patchy or nodular infiltrate. Tuberculosis may be found in any part of the lung, but upper lobe involvement is most common. Cavity formation, noncalcified round infiltrates, homogenously calcified nodules and military patterns are alternative findings on chest radiograph.
Which of the following is true regarding tetanus prophylaxis? Patients older than seven years of age should receive diphtheria-tetanus-acellular pertussis (DTaP or DT) prophylaxis Patients younger than seven years of age should receive tetanus-diphtheria (Td) or tetanus-diphtheria-acellular pertussis (Tdap) prophylaxis Tetanus immune globulin (TIG) prophylaxis is recommended for unimmunized patients with a high-risk wound Tetanus immune globulin (TIG) prophylaxis should be given at the same site as tetanus-diphtheria (Td) or tetanus-diphtheria-acellular pertussis (Tdap) prophylaxis
Correct Answer ( C ) Explanation: There are several different tetanus vaccine preparations, often given in combination with diphtheria (D or d component) and pertussis (the ap or aP component). These include DTP, DTap, Td, and Tdap. DTaP is the preferred vaccine for primary pediatric immunization. Uppercase indicates a larger concentration of the component, whereas lowercase indicates a smaller concentration. Tetanus vaccination is recommended for all ED patients with wounds. However, higher-risk tetanus-prone wounds include those more than six hours old, greater than 1 cm in depth, contaminated with dirt or soil, stellate, denervated, ischemic, or obviously infected. Adults with an uncertain childhood history of vaccination should receive a complete primary immunization series. In the presence of a high-risk wound, these patients should also receive a dose of human tetanus immunoglobulin (TIG) at a separate injection site. Previously immunized healthy adults should receive a Td or Tdap booster if it has been 10 or more years since their last dose. Immunity may wane more quickly in certain high-risk patients such as IV drug abusers, patients with immunosuppression, and the elderly, thus necessitating more frequent booster doses. The American Congress of Obstetricians and Gynecologists updated their guidelines and recommends Tdap during each pregnancy, irrespective of the patient's prior history of receiving Tdap.The new guidance was issued based on an imperative to minimize the significant burden of pertussis disease in vulnerable newborns, the reassuring safety data on the use of Tdap in adults, and the evolving immunogenicity data that demonstrate considerable waning of immunity after immunization. The DTaP preparation is preferred for children under the age of seven rather than Td or Tdap (B). When both TIG and tetanus toxoid (D) are given, they should be administered at separate sites. One Step Further
A previously healthy 25-year-old sexually active woman presents to your office with a complaint of a painful genital rash. Four days ago she started to feel sick with a headache and fever. The next day, she felt pain, burning, and tingling in her genital area. Physical exam reveals grouped, erythematous vesicles on the patient's labia majora, some of which are intact and others that are ruptured with ulcerations. Which of the following is the most likely diagnosis? Candidiasis Condyloma acuminata Herpes simplex virus Syphillis
Correct Answer ( C ) Explanation: There are two types of herpes simplex virus, herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2), which are both commonly seen worldwide. Historically HSV-1 was thought to cause orofacial manifestations while HSV-2 was thought to cause genital manifestations, however lesion location is not indicative of the strain of HSV involved. HSV is widespread, with most individuals having some evidence of either HSV-1 or HSV-2 infection during their lifetime. HSV-2 infection is more common in women than in men. Age of infection with HSV-2 is related to perinatal contact through the mother or once sexual activity begins. The clinical course of the virus depends on the type of virus, immune status and age of the host, and the affected site. Manifestations of HSV-2 infection include a prodrome of constitutional symptoms including fever, malaise, headache, and myalgias as well as localized symptoms at the affected site including pain, burning, and tingling. Shortly after the prodrome, herpetic vesicles appear. These lesions can rupture, leaving painful ulcerations. Clinical diagnosis should be verified with laboratory testing including viral culture, type-specific serologic tests, polymerase chain reaction (PCR), and direct fluorescence antibody. Treatment is with antiviral medication to slow the duration and severity of infection.
A 15-year-old girl presents with fever after returning from a trip to Africa. She states that she has been getting fevers every 3 days for the last 10 days. What test will confirm a diagnosis of malaria? Complete blood count Enzyme linked Immunosorbent assay (ELISA) Thick and thin smears VDRL
Correct Answer ( C ) Explanation: Thick and thin smears of a patient's blood sample are the gold standard for the diagnosis of malaria. Malaria is an acute febrile illness caused by 4 major types of Plasmodium: falciparum, ovale, vivax and malariae. The disease is transmitted to humans via the female Anopheles mosquito. Plasmodium sporozoites from Anopheles saliva invade and multiply in hepatic cells. Lysis of the hepatic cells leads to release of the parasite into the blood stream. The parasite subsequently invades red blood cells (RBCs) and feeds on hemoglobin. RBC lysis follows and is accompanied by fever. In addition to fever, patients often present with headache, nausea, chills, fatigue, abdominal pain and anemia. Unlike the other strains, P. falciparum can cause organ dysfunction and death. Although the history and physical with particular focus on travel history to endemic malaria regions suggests the diagnosis, the gold standard test is microscopic evaluation of a thick and thin smear of blood. Peripheral blood is stained with Giemsa or Wright stains that reveal the presence of the parasite
A 4-year-old boy is brought to his pediatrician for a rash. Three days ago the boy was febrile and complaining of a headache and nausea. Today, the fever abated and the rash appeared as shown above. Which of the following is the most appropriate management? Oral amoxicillin Oral diphenhydramine Reassurance and no other treatment Topical 1% hydrocortisone
Correct Answer ( C ) Explanation: This child with erythema infectiosum would best be managed with reassurance and no other treatment. Erythema infectiosum, or fifth disease, is common viral illness caused by human parvovirus B19. The incubation period is usually between 7-10 days. Erythema infectiosum is most commonly seen in school-aged children. Erythema infectiosum typically has biphasic illness, with nonspecific symptoms such as fever, malaise, coryza, and headache appearing first, followed by development of a rash 2-5 days later. The characteristic rash of erythema infectiosum has an intense fiery red, "slapped-cheek" appearance and circumoral pallor, and subsequent diffuse lacy exanthem covering the trunk and extremities. Affected adults typically have a less characteristic rash and are more likely to experience arthralgias. Parvovirus infection in pregnant mothers can result in fetal complications including miscarriage, premature labor, and non-immune hydrops fetalis. In immunocompetent children, the diagnosis of erythema infectiosum is based on clinical findings and patient history. Serological testing may be required in pregnant women, patients with hematologic disorders, or in immunocompromised patients. The majority of patients with erythema infectiosum require no or only symptomatic treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful for symptomatic relief of arthralgia and fever. Complications of parvovirus infection include transient aplastic crisis, chronic infection, myocarditis, and chronic arthritis.
28-year-old man presents to the emergency room with blurry vision, arm and trunk weakness, and dyspnea. Physical exam reveals bilateral fixed pupillary dilation, palsies of cranial nerves III, IV, and VI, and symmetrical upper extremity weakness. Physical exam is also notable for five puncture wounds on the left forearm. During his stay, the man develops respiratory failure and requires intubation. Which of the following is the most likely etiology of this man's condition? Autoimmune demyelination of peripheral nerves Cervical disk herniation causing spinal cord compression Clostridium botulinum infection Viral destruction of anterior horn cells in the spinal cord
Correct Answer ( C ) Explanation: This man most likely has wound botulism caused by Clostridium botulinum infection. Botulism is an uncommon, but potentially lethal neuroparalysis condition. Botulism is caused by a neurotoxin secreted by C. botulinum, a gram-positive, rod-shaped, obligate anaerobic bacteria that secretes spores. There are five main modes of botulism acquisition: foodborne, infant, wound, inhalation, and iatrogenic. In the United States, the majority of cases are infant botulism, followed by foodborne botulism and wound botulism. Infant botulism is most commonly associated with raw honey ingestion. Foodborne botulism is most commonly associated with home-canned food. Wound botulism is most commonly associated with puncture wounds and black tar heroin injection. Classic clinical manifestations of botulism include acute onset of bilateral cranial neuropathies, symmetric descending weakness, absence of fever, normal of slow heart rate, normal blood pressure, and no sensory deficits other than blurred vision. Cranial nerve involvement is common, which may manifest as diplopia, blurred vision, nystagmus, ptosis, and dysphagia. Other symptoms include urinary retention, constipation, and respiratory distress. Infants often present with hypotonia, drooling, and weak cry. Foodborne botulism is often accompanied by nausea, vomiting, abdominal pain, and diarrhea. Laboratory studies include stool analysis for spores, electromyography, and serum analysis of neurotoxin. The Center for Disease Control should be contacted as soon as the diagnosis of botulism is suspected so that equine serum antitoxin can be obtained. Additional management should include close respiratory status, antibiotics, and nutritional support. Viral destruction of anterior horn cells in the spinal cord (D) is the pathophysiology of poliomyelitis. Poliomyelitis is a viral illness that is vaccine-preventable. Poliomyelitis is characterized by profound asymmetrical muscle weakness. Poliomyelitis is spread via fecal-oral route.
An 18-year-old college student with a history of HIV (CD4+ 250) presents to the ED with headache, fever, and stiff neck for two days. He thought he had a cold and has been taking acetaminophen without relief of his headache. Vital signs are T 39.1°C, BP 100/50 mm Hg, HR 140 bpm, RR 30. He is sleepy but arousable. On exam, you place the patient's right hip and knee into a flexed position and then proceed to extend the knee. The patient winces when the knee is just beyond 90 degrees of flexion. You also note petechiae on his trunk and extremities with one small area on his right forearm that looks like a purple patch with a gray necrotic center. Which of the following is the most likely diagnosis? Cryptococcal meningitis Herpes encephalitis Meningococcemia Pneumococcal meningitis Toxoplasmosis
Correct Answer ( C ) Explanation: This patient has meningococcemia, a disease caused by Neisseria meningitidis. The clinical presentation ranges from a mild febrile illness to fulminant disease progressing to death within hours. Patients with meningococcal meningitis may present similarly to patients with meningitis of other origins with headache, photophobia, vomiting, fever, and signs of meningeal inflammation. Petechiae generally appear on the extremities and may progress to involve almost any body surface. Macular lesions may progress to purpura and ecchymoses in fulminant meningococcemia (purpura fulminans). The patient in this scenario exhibits a positive Kernig's sign, representing meningeal irritation, and has a purpuric lesion on his right forearm characterized by a gray necrotic center surrounded by a purple ring. Morbidity and mortality are high in meningococcemia but reduced with prompt recognition and immediate initiation of antibiotic therapy. Ceftriaxone and vancomycin are acceptable first-line agents
A 17-year-old woman presents with an ulcer on her labia. She denies pain, tenderness, and itching of the ulcer. Genital examination reveals a clean-based, sharply defined, circular ulcer on the labia minora. There are no other skin findings or lymphadenopathy. Which of the following is the most appropriate treatment regimen? A single dose of intramuscular ceftriaxone A single dose of oral azithromycin A single intramuscular injection of benzathine penicillin G Weekly intramuscular injections of benzathine penicillin G for 3 weeks
Correct Answer ( C ) Explanation: This patient has primary syphilis, an infection caused by the spirochete Treponema pallidum. This initial stage of infection is characterized by a clean-based, sharply defined, circular ulcer which develops 9-90 days after exposure. It is painless and usually solitary. After 2-6 weeks, the chancre resolves. Five to eight weeks later, a maculopapular, copper-colored rash develops. Associated symptoms at this stage include fever, malaise, and arthralgias. This is secondary syphilis. Primary, secondary and early latent syphilis (< 1 year from inoculation) are treated with single intramuscular injection of benzathine penicillin. Syphilis remains very susceptible to penicillin and this is the treatment of choice. Doxycycline, tetracycline, and erythromycin can be used in penicillin allergic patients.
A 22-year-old landscaper presents to the ED with a rash that began approximately three weeks ago. He reports it started with a single bump on his left forearm that has been oozing fluid. He subsequently developed lesions tracking up his arm. He denies any joint pain, decreased range of movement, fever, numbness, or weakness. On exam, he has an area of redness overlying a small papule and a rash spreading proximally as depicted in the image above. Which of the following is the most appropriate treatment for this condition? Acyclovir Hydrocortisone 1% Itraconazole Permethrin
Correct Answer ( C ) Explanation: This patient has sporotrichosis, a fungal infection transmitted by inoculation into the skin with the fungus Sporothrix schenckii. It is most commonly seen in gardeners, farmers, landscapers, and other agricultural workers. The infection is classically associated with a seemingly innocuous puncture wound from a rose bush thorn. Its characteristic rash begins with an ulcer or papule and then spreads proximally along lymphatic channels with skip lesions. Lymphocutaneous involvement, as depicted in the picture, is the most common manifestation. Treatment for this is three to six months of itraconazole.
A 17-year-old girl presents with the above rash a week after hiking in the woods. She does not report a tick bite. She otherwise has no symptoms. What management is indicated? Ceftriaxone 2 grams for 14 days Chloramphenicol 1 gram for 21 days Doxycycline 100 mg twice a day for 3 weeks No treatment while awaiting diagnostic testing
Correct Answer ( C ) Explanation: This patient presents with erythema migrans, the typical rash seen in early Lyme disease and requires 3 weeks of treatment with oral doxycycline. Lyme disease is an illness caused by transmission of Borrelia burgdorferi bacteria from a tick. The common vector is Ixodes scapularis. Transmission from tick to person requires attachment and feeding for more than 48 hours. Thus, early removal of ticks can prevent transmission. Typically, erythema migrans presents 7 to 10 days after infection and is proceeded by a non-specific constitutional symptoms (fever, malaise, fatigue etc.). Approximately 90% of patients report the presence of the rash. The rash begins as a small papule at the site of infection and gradually expands (1-2 cm/day). Typically, the rash will have central clearing but this is not universal. Further hematogenous spread of B. burgdorferi can cause numerous symptoms including arthralgias, neurologic manifestations, heart block etc. The diagnosis of Lyme disease is based primarily on clinical features but serologic or ELISA testing can be used to confirm the diagnosis. Prompt treatment of early manifestations can both shorten symptom duration and prevent progression to later disease stages. Early Lyme disease should be treated with oral doxycycline 100 mg twice a day for 21 days. Amoxicillin and cefuroxime are alternatives to doxycycline. You should also make sure that you obtain a negative pregnancy test in all females of child bearing age before starting on doxycycline.
A 23-year-old man presents with fever, headache, and myalgias ten days after hiking in the woods in South Carolina. Vital signs are BP 110/70 mm Hg, HR 105 beats/minute, RR 18 breaths/minute, and temperature 102 °F. On physical examination, he has right upper quadrant abdominal tenderness and scleral icterus. What is the most appropriate therapy? Amoxicillin 500 milligrams orally three times daily Ceftriaxone 1 grams intravenously every 12 hours Doxycycline 100 mg orally two times daily Rifampin 600 mg orally once daily
Correct Answer ( C ) Explanation: This patient presents with signs and symptoms consistent with human ehrlichiosis, a tick-borne illness seen primarily in the South Central and South Atlantic United States. The peak incidence of the disease is typically the summer months (June-August). There are multiple members of the Ehrlichia family; however, they are all gram-negative, obligate intracellular coccobacilli that reside within circulating leukocytes. Signs and symptoms begin approximately nine days after discovery of the tick and 90% of patients recall the bite. Signs and symptoms include abrupt onset of fever, headache, myalgias, and rigors with less frequently associated GI symptoms. Complications, although uncommon, include optic neuritis, ARDS, meningitis, pericarditis, renal failure, and DIC. Laboratory studies characteristically reveal leukopenia, thrombocytopenia, and elevated liver function tests. Management of ehrlichiosis is doxycycline 100 mg two times daily for 7-14 days, regardless of age. The vast majority fully recover without any residual morbidity. Rifampin 600 mg PO once daily (D) is the appropriate treatment for patients with ehrlichiosis who have a life-threatening allergic reaction to doxycycline or other tetracyclines
An 8-year-old boy presents with fever for 3 days. He had a fever, cough and nasal congestion 2 days ago and this morning began with a rash. Examination reveals maculopapular, red lesions over the face, neck and chest. You also note conjunctivitis. He is otherwise well appearing. What management is indicated? Ceftriaxone Isolation of patient from family Supportive care Tetracycline
Correct Answer ( C ) Explanation: This patient presents with symptoms consistent with measles requiring supportive care. Measles is a highly contagious viral illness spread by infectious droplets. The incubation period for the virus is 10-14 days and patients are contagious 2 days prior to the onset of symptoms to 4 days after the rash appears. The rash is typically preceded by fever, which increases daily for 5-6 days, and malaise. Cough, coryza and conjunctivitis begin about 24 hours after the onset of fever. Koplik's spots, a pathognomonic finding, appear on the second day of illness. They are small, bright red spots with blue-white centers appearing on the buccal mucosa. Rash follows on the fourth to fifth day of the illness. The rash is characterized by maculopapular lesions beginning on the forehead and face and spreading to the trunk, arms and legs. Treatment for measles focuses on supportive care and recognition of bacterial complications. Isolation of infected patients is usually not helpful as exposure usually occurs prior to identification of the disease. Additionally, patients are not contagious after the rash has been present for 5 days. Administration of human immune serum globulin (ISG) can modify the course of disease if given within 6 days of exposure. Live measles virus vaccine may prevent measles if given within 72 hours of exposure
A 27-year-old woman presents with fever. She recently returned 11 days ago from a camping trip in Florida. In the last 24 hours she has developed a fever, headache, myalgias, and shaking chills. Laboratory testing is notable for elevated transaminases and thrombocytopenia. Which of the following is the most appropriate antibiotic to administer? Ciprofloxacin Erythromycin Tetracycline Trimethoprim-sulfamethoxazole
Correct Answer ( C ) Explanation: This patient's symptoms are consistent with ehrlichiosis. There are several species of Ehrlichia that cause infection in the United States and the species depends on the geographic location. The disease is spread to humans through a tick vector requiring a bite. On average, symptoms begin nine days after discovery of the tick bite. As opposed to other tick-borne illnesses like Lyme, ehrlichiosis is characterized by the abrupt onset of fever, headache, myalgias and shaking chills. Vomiting and diarrhea occur less frequently and up to 1/3 of patients develop a rash. Leukopenia, thrombocytopenia, and elevated liver enzymes occur in 50 to 90% of patients. Tetracycline and doxycycline are the antibiotics of choice and curative when administered for 7 to 14 days. Rifampin is an acceptable alternative. If patients do not improve after six to seven days, an alternative diagnosis should be considered. The diagnosis is made based on the clinical features and exposure, but is confirmed through several laboratory testing options: 1) antibody titers; 2) PCR assay for organism-specific DNA; 3) Identification of morulae in leukocytes; 4) Immunostaining on biopsy; 5) Culture.
A 47-year-old man presents for evaluation of a whitish discoloration on his tongue for the last several days. He denies any fever or other systemic signs. On examination, the following findings are seen on the image above. You are unable to scrape the base of the plaque off with a tongue depressor. Which of the following tests is likely to be positive? Gram stain demonstrating large, ovoid, gram-positive yeast KOH prep Rapid HIV Rapid strep
Correct Answer ( C ) Explanation: This patient's tongue demonstrates the white corrugated plaques of oral hairy leukoplakia. This is a disease of the lateral tongue caused by infection of the squamous epithelium with Epstein-Barr virus. Most commonly the infection is localized to the lateral portion of the tongue, although in rare cases it may involve the floor of the mouth, palate or buccal mucosa. Clinically this may be difficult to differentiate from thrush caused by candida. However, the lesions of oral hairy leukoplakia cannot be scraped off the surface. Although caused by Epstein-Barr, it is rarely seen in conditions other than patients with HIV infection.
A 45-year-old human immunodeficiency positive patient is seen in clinic. He is non-compliant with his antiretroviral therapy and his CD4 count is noted to be 150 cells/µL. He is given a prescription for trimethoprim-sulfamethoxazole for prophylactic treatment of which of the following opportunistic infections? Coccidioidomycosis Mycobacterium avium complex Pneumocystis jiroveci pneumonia Tuberculosis
Correct Answer ( C ) Explanation: Trimethoprim-sulfamethoxazole is prophylactic treatment for Pneumocystis jiroveci pneumonia. Untreated HIV infection and HIV-related immunosuppression significantly increase the risk of acquiring opportunistic infections due to bacteria, viruses, fungi, and protozoa. These opportunistic infections were a major source of morbidity and mortality in HIV-infected patients prior to the development of effective antiretroviral therapy and still occur today, mostly in patients who are not receiving therapy. Substantial advances in the prevention of opportunistic infections have been achieved. These strategies involve the use of antimicrobials, immunizations, and public health measures. Antimicrobial agents can be administered to immunocompromised individuals with HIV-infection to decrease the risk of developing certain opportunistic infections such as P. jiroveci pneumonia, toxoplasmosis, M. avium complex infection, and tuberculosis. When to initiate such therapy depends upon the CD4 count. Trimethoprim-sulfamethoxazole is recommended to prevent Pneumocystis jiroveci in those with CD4 counts < 200 cells/µL. The risk of PCP without prophylaxis is 40 to 50% per year in those with a CD4 count < 100 cells/µL.
Which of the following cerebrospinal fluid analyses is most consistent with viral meningitis? WBC 2900, glucose 20, protein 95 WBC 350, glucose 15, protein 190 WBC 400, glucose 20, protein 270 WBC 525, glucose 75, protein 90
Correct Answer ( D ) Explanation: Normal adult cerebrospinal fluid (CSF) contains no more than 5 leukocytes/µL. More than 5 cells/µL should be considered evidence of CNS infection. Below is a table representing the typical spinal fluid results for meningeal processes. Although the diagnosis of viral meningitis is often straightforward, there can be an overlap of CSF findings in patients with early and partially treated bacterial meningitis, making the distinction somewhat difficult. Moreover, while neutrophils tend to predominate in bacterial meningitis, they may be present in the CSF for the first 24 hours with viral meningitis.
A 46-year-old man accidentally cut his hand on a loose dirty screw one week ago. He cleaned the area with water a few hours after the injury. He was his usual self until one week later when he began to complain of a stiff neck and difficulty opening his mouth. What is the most likely diagnosis? Botulism Diphtheria Meningitis Tetanus
Correct Answer ( D ) Explanation: Tetanus is a disease of the nervous system caused by an anaerobic bacterium, Clostridium tetani, that is mostly found in the soil and whose toxin is transmitted to the bloodstream by a break in the skin. Tetanus is typically a result of a wound on the skin that is contaminated by soil, feces, dirt, or saliva or an injury such as a puncture wound, skin avulsion, crushing wound, burn, or frostbite. Trismus, or lockjaw, is the most common clinical finding which is a result of excessive muscle spasms. Other classic findings include a stiff neck, stiff abdomen, dysphagia, and episodes of apnea due to pharyngeal muscle contraction. Because of vaccinations, the likelihood of contracting tetanus has been significantly reduced over the years. Treatment includes wound management, administration of a tetanus toxoid-containing vaccine and tetanus immune globulin, antimicrobial therapy with metronidazole, and controlling the muscle spasms.
A 17-year-old boy is seen in the clinic because of a skin lesion. He first noted a bump on his penis that became ulcerated. He denies any pain. He admits he is sexually active and has had multiple sexual partners. He denies the use of contraception. On physical exam, there is a 1 centimeter ulcer with a raised, indurated margin on the penile head accompanied by bilateral inguinal lymphadenopathy. Which of the following is the most likely etiologic agent? Haemophilus ducreyi Herpes simplex virus Klebsiella granulomatis Treponema pallidum
Correct Answer ( D ) Explanation: A boy has a single, painless ulcer that is suspicious for primary syphilis. Syphilis is a chronic infection caused by the bacterium Treponema pallidum. Transmission of T. pallidum usually occurs via direct contact with an infectious lesion during sex. It is thought that the spirochete gains access via disrupted epithelium at sites of minor trauma. Primary syphilis occurs after an average incubation period of two to three weeks. A painless papule appears at the site of inoculation that soon ulcerates to produce the classic chancre of primary syphilis, a one to two centimeter ulcer with a raised, indurated margin. The ulcer generally has a non-exudative base and is associated with mild to moderate regional lymphadenopathy that is often bilateral. Such lesions usually occur on the genitalia, but occasionally patients may develop chancres at other sites of inoculation. Chancres heal spontaneously within three to six weeks even in the absence of treatment. Since the ulcer is painless, many patients do not seek medical attention, a feature that enhances the likelihood of transmission. The mechanism of healing is unknown but is thought to be a consequence of local immune responses. While the chancre represents initial local infection with T. pallidum, widespread dissemination of the spirochete also occurs early during the primary stage of infection. The chancre of primary syphilis is best diagnosed by dark field microscopy Haemophilus ducreyi (A) causes a chancroid that forms a deep, undermined, purulent ulcer that may be associated with painful inguinal lymphadenitis. Herpes simplex virus (B) causes genital herpes characterized by multiple, shallow, and tender ulcers that may be vesicular. Klebsiella granulomatis (C) causes granuloma inguinale (donovanosis), which is a genital infection that is usually sexually acquired and is most prevalent in tropical regions. It causes pseudo-buboes in the inguinal area, which are typically associated with ulcers on the genitalia. Pseudo-buboes are caused by subcutaneous granulation and are eventually broken down and replaced by ulcers.
In patients with sickle cell disease, exposure to which of the following viruses can result in an aplastic crisis? Coxsackie A 16 Human Herpes Virus 6 Paramyxovirus Parvovirus B19
Correct Answer ( D ) Explanation: Aplastic crisis is defined as having a reticulocyte count of less than 1%. Patients with sickle cell disease who are infected with Parvovirus B19 are at risk for developing an aplastic crisis. Parvovirus B19 is the causative agent of Fifth disease and can lead to an aplastic crisis by causing a temporary arrest of red blood cell production. This is characterized by a sudden decrease in hemoglobin production by bone marrow resulting in severe anemia. Patients may present with pallor, lethargy, and shock. Treatment includes hemodynamic support and blood transfusion.
Which of the following is true regarding the characteristic rash of chickenpox? Lesions appear over 2-4 weeks with multiple stages present at once Lesions appear over 2-4 weeks with one stage present at a time Lesions appear over days and fade by the third day Lesions appear over days with multiple stages present at once
Correct Answer ( D ) Explanation: Chickenpox is a highly contagious but generally benign and self-limited viral disease caused by the varicella-zoster virus (also known as human herpesvirus 3). The disease is characterized by the sudden onset of fever, malaise, and a pustular maculopapular rash that can occur anywhere on the skin or mucus membranes. The lesions then become vesiculated followed by scabbing over the course of 3-4 days before resolving. Skin lesions appear in crops with multiple lesions of various stages appearing on the skin at the same time. Uncomplicated infection is generally treated with supportive measures, including antipyretic, antipruritic, and pain control medications. Antivirals such as acyclovir, valacyclovir, and foscarnet may also be initiated in severe disease or immunosuppressed individuals. Parents should be cautioned to avoid giving their children aspirin or aspirin-containing medications due to the risk of developing Reye's syndrome. The lesions of chickenpox appear suddenly rather than gradually (A). Smallpox lesions may appear similar to chickenpox lesions, however, they are found in the same stage (B) of development. Rubella (German measles) is associated with the sudden onset of a maculopapular rash that first appears on the face then rapidly spreads inferiorly to the neck, trunk, and extremities and fades by the third day (C).
A diagnosis of acquired immunodeficiency syndrome is established in which of the following clinical scenarios? AHuman immunodeficiency virus positive with a CD4 count of 300 cells/µL and acute herpes simplex infection under 1 month duration BHuman immunodeficiency virus positive with a CD4 count of 350 cells/µL and community acquired pneumonia CHuman immunodeficiency virus positive with a CD4 count of 400 cells/µL and oral candidiasis DHuman immunodeficiency virus positive with a CD4 count of 450 cells/µL and disseminated mycobactererium avium complex infection
Correct Answer ( D ) Explanation: Human immunodeficiency virus (HIV) positive with a CD4 count of 450 cells/µL and disseminated mycobactererium avium complex infection is considered diagnostic of acquired immunodeficiency syndrome (AIDS). AIDS is the outcome of chronic HIV infection and consequent depletion of CD4 cells. It is defined as a CD4 cell count < 200 cells/µL or the presence of any AIDS-defining condition regardless of the CD4 cell count. Most opportunistic infections are unlikely to occur in patients with a CD4 cell count > 200 cells/µL which is why this is the threshold value used to define AIDS. Mycobacterium avium complex is considered to be an AIDS-defining condition. AIDS-defining conditions are opportunistic illnesses that occur more frequently or more severely because of immunosuppression. These include mainly opportunistic infections, but also certain malignancies, as well as conditions without clear alternative etiology thought to be related to uncontrolled HIV infection itself, such as wasting or encephalopathy. Prior to introduction and widespread use of combination antiretroviral therapy (ART), AIDS-associated illnesses were the principal cause of morbidity and mortality associated with HIV infection. Pneumocystis jiroveci pneumonia was the most common initial opportunistic illness, followed by esophageal candidiasis, Kaposi's sarcoma, wasting syndrome, and disseminated Mycobacterium avium infection.
A 16-year-old girl presents to the Emergency Center with complaints of vaginal discharge. Speculum exam reveals a frothy discharge and punctate hemorrhages of the cervix. What is the treatment of choice? Azithromycin Ceftriaxone Doxycycline Metronidazole
Correct Answer ( D ) Explanation: The above patient has findings of acute cervicitis as manifest by vaginal discharge and cervical changes on speculum exam. The punctate hemorrhages on the patient's cervix describe "strawberry cervix," which is a classic finding of trichmoniasis, caused by Trichomonas vaginalis. Notably, however, strawberry cervix is estimated to be present in only 2% of cases and cannot be utilized to rule out trichmoniasis. Frothy, green vaginal discharge is also considered classic for Trichomonas, but the consistency and color the discharge may vary considerably. In addition to discharge, affected patients may complain of dysuria, urinary frequency, dyspareunia, or lower abdominal pain. Others are completely asymptomatic but still contagious. As signs and symptoms are neither sensitive nor specific for diagnosis, a wet prep should be obtained. If the motile trichomonads are not noted but trichmoniasis is suspected, the specimen should be sent for culture. The treatment of choice for is metronidazole. Tinidazole is an alternative therapy.
A 13-year-old boy with a history of asthma presents to your office with complaints of fever, cough, sore throat, muscle aches, and headache for one day. Rapid influenza diagnostic testing reveals a positive result for influenza B virus. Which of the following is the most appropriate therapy? Amantadine Aspirin Azithromycin Oseltamivir
Correct Answer ( D ) Explanation: Influenza is an acute respiratory illness caused by influenza A or B viruses. It is extremely contagious and causes approximately 20,000 deaths annually in the United States during the winter season. It is transmitted via airborne droplets released when an infected person sneezes or coughs. Patients present with complaints of fever, muscle aches, sore throat, cough, nasal discharge, and headache. Groups considered high risk for complications include older adults, young children, pregnant women, immunocompromised individuals, and patients with chronic pulmonary disorders, including asthma. Diagnosis of influenza is often a clinical one, however laboratory testing should be done on patients deemed to be at high risk for complications or anyone with symptoms severe enough to merit hospitalization. For most healthy children, influenza is a self-limiting, mild illness. Treatment with antiviral medication, such as oseltamivir is indicated for patients deemed high risk for complications, those who are hospitalized with influenza symptoms, or in healthy children who would benefit from a decrease in duration and severity of symptoms.
A 23-year-old previously healthy man presents to your office with complaints of fever, cough, sore throat, muscle aches, and headache for the past four days. He appears mildly ill, but is well hydrated, and tolerating oral intake. Rapid influenza diagnostic testing reveals a positive result for influenza B virus. Which of the following is the most appropriate next step in management? Initiate course of azithromycin Initiate course of oseltamivir Referral to the emergency department for evaluation Supportive care
Correct Answer ( D ) Explanation: Influenza is an acute, contagious respiratory illness caused by influenza A or B viruses. It is one of the most common infectious diseases and causes significant morbidity and mortality each year. Occurring seasonally in the winter months, influenza infection generally presents with patient complaints of fever, cough, sore throat, muscle aches, and headache. Diagnosis of influenza is often made clinically, and rapid testing is frequently used in the clinical setting, however has only a moderate specificity. Confirmation of influenza infection is with reverse transcription-polymerase chain reaction (RT-PCR) or viral culture of nasopharyngeal or throat secretions. For most healthy individuals, influenza is a self-limiting, mild illness that may be treated with supportive care. Prevention is with the annual influenza vaccine which is recommended for everyone over the age of 6 months. Treatment of influenza with antiviral medication, such as oseltamivir (B) is indicated for patients deemed high risk for complications, those who are hospitalized with severe influenza symptoms, or in healthy individuals who would benefit from a decrease in duration and severity of symptoms.
An otherwise healthy 27-year-old man presents with several days of fever, drenching sweats, and shaking chills one week after returning from India. Which of the following is most likely to reveal the diagnosis? Blood cultures Hepatitis panel India ink stain Thick and thin peripheral smear
Correct Answer ( D ) Explanation: Malaria must be considered in any patient with a history of fever and travel to an endemic region. Four species cause disease in humans: Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax, and Plasmodium malariae. P. falciparum is the most virulent form of the disease able to cause severe organ dysfunction and death. The lifecycle of the organism causes irregular or cyclic fevers in patients that is associated with RBC lysis. Other symptoms include headache, nausea, abdominal pain and upper respiratory complaints. The gold standard includes thick and thin smears of the blood viewed under light microscopy to identify the parasite.
A 13-month-old boy presents to your office with fever and rash. Five days ago, he developed a fever of 103°F and had symptoms of cough, rhinorrhea, and eye redness. Yesterday, he woke up with a rash affecting his head and face that is now spreading to the rest of his body. Which of the following is most likely to confirm the diagnosis? Rapid influenza diagnostic testing Rapid strep testing Serum Epstein-Barr virus anti-viral capsid antigen Serum rubeola virus IgM antibody
Correct Answer ( D ) Explanation: Measles is a viral illness caused by the rubeola virus. It is one of the most contagious infectious diseases and is spread through contact with respiratory droplets. The virus can live for up to two hours in an area where the infected person was coughing or sneezing. Vaccine programs have helped to significantly decrease the incidence of measles, with the majority of cases being linked to international travel. In the past few years, there has been an increase in cases, mostly among unvaccinated individuals. Clinical manifestations of measles include a prodrome of high fever and "the 3 C's": cough, coryza and conjunctivitis, followed by the measles exanthem. The classic presentation of the exanthem is a maculopapular, erythematous, blanching rash that begins on the head and face and spreads downward, occurring two to four days after onset of fever. The most common laboratory test used in the diagnosis of measles is serum measles IgM antibody. Patients being evaluated for testing should be isolated and additional testing including throat or nasopharyngeal swab for viral culture and a urine sample for viral culture should be ordered. Measles is a reportable infection, and suspected cases should be reported to the local health department within 24 hours.
Which of the following is the hallmark characteristic of mumps? Cough, coryza, and conjunctivitis Epididymoorchitis Maculopapular rash Nonsuppurative parotid swelling
Correct Answer ( D ) Explanation: Mumps is a viral illness characterized by fever, swelling, and tenderness of the salivary glands, with the parotid gland most commonly affected. The disease is seen most commonly in the winter and spring months and is communicable 7-10 days after the onset of parotitis. Nonsuppurative parotid swelling is the hallmark of mumps. The swelling can be unilateral or bilateral and is sometimes associated with trismus. Less commonly, patients experience epididymoorchitis, which also can be unilateral or bilateral, and meningitis. The CSF in these cases usually demonstrates a lymphocyte pleocytosis and low glucose. Rare complications include transverse myelitis, Guillain-Barré syndrome, pancreatitis, myocarditis, and deafness. Treatment is supportive.
A 5-year-old girl presents with a blanching, erythematous rash that appeared four days after being bitten by a tick. She also complains of fever, abdominal pain, and myalgias. Laboratory studies are notable for thrombocytopenia. Which of the following is the most appropriate therapy? Amoxicillin Chloramphenicol Dicloxacillin Doxycycline
Correct Answer ( D ) Explanation: This child most likely has Rocky Mountain spotted fever (RMSF) and is best managed with doxycycline. RMSF is a tick-borne infectious disease that occurs throughout the North, Central, and South America. Rickettsia rickettsii is the etiologic pathogen, which is transmitted to humans by bite of ticks. R. rickettsii is a gram-negative, nonmotile, obligate intracellular parasite. In the United States, RMSF is the most common rickettsial infection. RMSF is most prevalent in the southeastern and southcentral United States. Risk factors for RMSF include ages 5-10 years and 40-60 years, male sex, exposure to dogs, and living near wooded areas or who have tall grass. Incubation period is typically 5-7 days after exposure. RMSF classically presents with fever, headache, rash, and a history of a tick bite. Other common complaints include malaise, myalgias, arthralgias, nausea, and abdominal pain. A blanching, erythematous rash occurs in the majority of patients. The rash of RMSF characteristically affects the palms and soles. A normal white blood count and thrombocytopenia are common laboratory findings commonly found in RMSF. Serological testing or skin biopsy can be used to confirm the diagnosis, but are not required in cases with clinical signs and symptoms consistent with RMSF. Oral or intravenous doxycycline is the treatment of choice in children and non-pregnant adults. Chloramphenicol is the preferred therapy for pregnant women, who are in the first and second trimester. Prophylactic antibiotics are not recommended following a tick bite. Mortality rates vary from 30-80% in untreated cases of RMSF.
A 35-year-old man presents to his primary care provider complaining of a rash. Physical exam is notable for diffuse lymphadenopathy and a diffuse macular rash that is distributed symmetrically and involves the palms and soles as show above. The man has previously had an anaphylactic allergic reaction to amoxicillin. Which of the follow is the most appropriate treatment? Intramuscular ceftriaxone Intramuscular penicillin G Oral azithromycin Oral doxycycline
Correct Answer ( D ) Explanation: Oral doxycycline is the treatment of choice for secondary syphilis in patients who are allergic to penicillin. Syphilis is a bacterial infection that is primarily sexually transmitted. Syphilis is caused by Treponema pallidum, a spirochete. Transmission of T. pallidum occurs through direct exposure to open lesions, which appear in primary and secondary syphilis. There are four stages of syphilis: primary, secondary, latent, and tertiary syphilis. The majority of new cases of syphilis in the United States occur among men who have sex with men. Primary syphilis is characterized by a painless chancre that usually develops within 10-90 days after inoculation. Approximately 25% of individuals with untreated primary syphilis will develop secondary syphilis weeks to months after development of the chancre. A diffuse, symmetrical macular or papular rash is the most characteristic finding of secondary syphilis. The individual lesions are discrete, round, 1-2 cm in diameter and reddish-brown, or copper, in color. Lymphadenopathy occurs in the majority of patients. Neurosyphilis, gummatous syphilis, and cardiovascular syphilis are common manifestations of late syphilis. Penicillin is the treatment of choice for primary and secondary syphilis. In penicillin allergic patients, doxycycline is the first-line agent. All cases of syphilis should be reported to the Centers for Disease Control.
A 7-day-old infant presents for eye discharge. He was born at home with the aid of a midwife. On exam, the infant has copious mucopurulent discharge from both eyes, swollen eyelids, and chemosis. Which of the following is the most appropriate treatment? Ciprofloxacin ophthalmic Erythromycin ophthalmic Intramuscular ceftriaxone Oral erythromycin
Correct Answer ( D ) Explanation: Oral erythromycin is the treatment of choice for neonatal chlamydial conjunctivitis. Chlamydia trachomatis is the most common sexually transmitted infection in the United States. Conjunctivitis and pneumonia are the most frequent clinical manifestations of neonatal C. trachomatis infections. C. trachomatis is the most common cause of conjunctivitis in the newborn. Vaginal delivery has the highest risk transmission to the newborn. The incubation period for neonatal chlamydial conjunctivitis is 5-14 days after delivery. Neonates with chlamydial conjunctivitis typically present with mucopurulent ocular discharge, eyelid swelling, and erythematous conjunctiva. Culture is the gold standard for diagnosing chlamydial conjunctivitis. The American Academy of Pediatrics and the Centers for Disease Control both recommend oral erythromycin as the first-line treatment for chlamydial conjunctivitis. Oral azithromycin is an alternative to oral erythromycin. The infant's mother and sexual partners should also be screened and treated for chlamydia. The best method for preventing chlamydial conjunctivitis is screening and treating the mother. Topical prophylactic antibiotics are ineffective at preventing chlamydial conjunctivitis.
A 24-year-old man presents with complaints of the "flu" for the past five weeks. He complains of having a fever, cough, and runny nose about one month ago that has since resolved. Now he complains of a chronic dry cough that "comes in fits" and seems to be worse at night and often wakes him from sleep. He currently denies fevers, chills, rhinorrhea, or nasal congestion. He saw his primary care physician two weeks ago who obtained a chest X-ray (negative) and diagnosed him with a viral infection. Your physical exam reveals a well-appearing male who is in no acute distress. The cardiopulmonary exam is within normal limits and a repeat chest X-ray in the ED is unremarkable. Which of the following is the most likely diagnosis? Aspirated foreign body Congestive heart failure Cough-variant asthma Pertussis
Correct Answer ( D ) Explanation: Pertussis (whooping cough) primarily affects children younger than 10 years old, but the number and proportion of cases involving adults are increasing. Pertussis is difficult to diagnose. It typically begins with a catarrhal stage (rhinorrhea and mild cough), which can last up to two weeks. This is followed by paroxysms of an irritating cough. The repeated violent coughs consist of short expiratory bursts followed by an inspiratory gasp, or "whoop," that gives the disease its characteristic name. However, the whoop is often absent in adults and in infants younger than six months old. Although the diagnosis is based primarily on the characteristic clinical features, definitive diagnosis is made through the culture of nasopharyngeal aspirate on specific culture medium. Direct fluorescent antibody (DFA) and polymerase chain reaction (PCR) can be used for confirmation. Cough-variant asthma (C) is a type of asthma in which the main symptom is a dry, nonproductive cough and is not associated with classic asthma symptoms such as wheezing or shortness of breath. This condition is similar to pertussis in that both are associated with a chronic cough, but pertussis is also associated with a catarrhal period (coryza, mild fever, nonproductive cough).
Which of the following is an example of primary prevention? Eliminating dust and pollen for an asthmatic Ophthalmoscope exam in diabetics Papanicolaou test Varicella vaccine
Correct Answer ( D ) Explanation: Prevention traditionally has been divided into three categories: primary, secondary, and tertiary. Primary prevention targets individuals who may be at risk to develop a medical condition and intervenes to prevent the onset of that condition. Examples include childhood vaccinations, water fluoridation, smoking cessation, and education about safe sex. The varicella vaccine is an example of primary prevention.
A 33-year-old wrestler presents with a worsening skin infection. He was seen in the ED two days prior and had an incision and drainage of an abscess on his left arm. The drainage has decreased but now he has an area of erythema that has expanded around his original abscess and a second purulent lesion on his leg. Which of the following is the most appropriate antibiotic choice? Amoxicillin-clavulanic acid Cephalexin Ciprofloxacin Trimethoprim-sulfamethoxazole
Correct Answer ( D ) Explanation: Purulent skin infections are most commonly caused by Staph aureus. Since the early 2000s, approximately 60% of these infections are from community-associated methicillin-resistant Staph aureus (MRSA). An abscess forms when bacteria replicate near the base of a hair follicle or other location beneath the epidermis. On physical examination, the area is erythematous, warm, tender, indurated and fluctuant in the center. On bedside ultrasound, the fluid cavity is easily identified as a hypoechoic space using the high-frequency linear probe. Treatment of abscesses is surgical with incision and drainage. Antibiotics are not indicated. However, in certain situations antibiotics are part of the treatment plan including: severe or extensive disease which includes multiple sites of infection, severe associated cellulitis, systemic illness, immunocompromise, locations where drainage is not possible, or failure to respond to medical treatment. When antibiotics are prescribed, coverage against community-associated MRSA is mandatory. Trimethoprim-sulfamethoxazole has widespread activity against the organism in the US.
Which of the following patients is at greatest risk of developing West Nile meningoencephalitis? 22-year-old man status postrenal transplant 3-year-old girl who is unvaccinated 58-year-old man with diabetes and hypertension 82-year-old woman with dementia
Correct Answer ( D ) Explanation: West Nile virus is a zoonotic infection that first appeared in the U.S. along the eastern seaboard in 1999 but can now be found nationwide. West Nile encephalitis (WNE) is endemic in the Middle East, Africa, and Asia. Birds serve as the primary host, and it is transmitted by the bite of a mosquito. WNE usually occurs in the summer, when mosquitoes, wild migratory birds, and humans are in close proximity outdoors. Most people infected with West Nile virus are asymptomatic. When present, symptoms are typically mild and include fever, headache, and fatigue. Severe disease, however, can cause central nervous system manifestations including meningitis, encephalitis, and myelitis. The biggest risk factor, by far, for neuroinvasive West Nile disease is advanced age.
A 21-year-old woman presents with sudden onset of right-sided hearing loss for 1 day. She also has severe vertigo associated with nausea and vomiting. The patient reports URI symptoms over the previous 3 days. Currently, she feels fullness and mild otalgia in her right ear and abnormal taste when she eats food. On exam, you note a few vesicles anterior to her right ear. She has drooping of the right side of her face and cannot wrinkle the right side of her forehead. Which of the following is the best treatment for this patient? Antibacterial otic drops Head CT scan and neurology consult Herpes zoster vaccine Prednisone and acyclovir
Correct Answer ( D ) Explanation: Ramsay Hunt syndrome is an acute peripheral facial neuropathy associated with an erythematous vesicular rash of the skin of the ear canal, auricle (also termed herpes zoster oticus), or mucous membrane of the oropharynx. It is caused by reactivation of herpes zoster in the geniculate ganglion. This nerve cell ganglion is responsible for movements of the facial muscles, sensation of parts of the ear and ear canal, taste function of the tongue, and lubrication of the eyes and oral mucosa. Because the vestibulocochlear nerve is close to the geniculate ganglion, patients may complain of tinnitus, hearing loss, and vertigo. Patients usually present with paroxysmal pain deep within the ear. The pain often radiates outward into the pinna of the ear and may be associated with a more constant, diffuse, and dull background pain. The onset of pain usually precedes the rash by several hours and even days. Poor prognostic factors for good functional recovery include age older than 50 years, complete facial paralysis, and lack of CN VII nerve excitability. Combined therapy with prednisone and acyclovir are the most commonly used and are most effective if started within the first 3 days of symptom onset.
A 17-year-old woman presents with a fever, myalgias, and headache. She noted a rash that began 4 days after she noted her fever. The macular rash began on her wrists and ankles and spread toward her chest. She recently returned from hiking the Appalachian Trail in North Carolina about 1 week ago and is concerned about her symptoms. Which of the following is the most likely diagnosis? Babesiosis Colorado tick fever Lyme disease Rocky Mountain spotted fever
Correct Answer ( D ) Explanation: Rocky Mountain spotted fever (RMSF) is a life-threatening infection caused by Rickettsia rickettsia transmitted by dog ticks. Its name derives from its original description in Montana and Idaho in the late 19th century and from the typical petechial rash occurring initially on the wrists and ankles and spreading centripetally (towards the center). It may also involve the palms and soles. Abrupt onset of fever, severe headache, and myalgias are the most common presenting symptoms 5-7 days after the tick bite. Babesiosis (A) is a malaria-like illness caused by Babesia microti protozoan. It is transmitted by Ixodes ticks in the northeastern United States; it also has been acquired by transfusion. Like malaria, the protozoan infects red blood cells, causing fever, drenching sweats, myalgias, and headache. It is occasionally associated with a rash. Colorado tick fever (B) is caused by the Coltivirus and transmitted by the dog tick (similar to RMSF) in the western United States. Patients present 3-6 days after a bite with sudden fever, headache, myalgias, and photophobia. A transient petechial rash may occur. In 50% of cases, symptoms resolve and then recur after 3 days. Lyme disease (C) is transmitted by the bite of an Ixodes scapularis tick and is the most common vectorborne disease in the United States. Early infection is associated with the classic erythema migrans rash, a circular lesion with central clearing or erythema at the site of a tick bite.
An unimmunized child has had a mild fever for several days. Today, the child is brought to the clinic because of the development of a rash. The rash is a pink discrete macular eruption mostly on the face and trunk. Postauricular and suboccipital lymph nodes are palpable. The child has a low-grade fever, but does not appear sick. Which of the following is the most likely diagnosis? Erythema infectiosum Measles Roseola Rubella
Correct Answer ( D ) Explanation: Rubella (German measles) is a systemic disease caused by a togavirus transmitted by inhalation of infective droplets. Mild symptoms including fever, malaise, and coryza may occur first after exposure. A pink maculopapular rash begins on the head and neck, spreads downward, and fades within 3 days. Posterior cervical and postauricular lymphadenopathy occurs 5-10 days before the rash. The characteristic lymphadenopathy and lack of systemic symptoms of this patient are most consistent with rubella.
A 16-year-old man presents with three days of crampy abdominal pain and bloody diarrhea that started after eating a chicken salad sandwich. He endorses decreased fluid and solid intake. He denies vomiting. His blood pressure is 110/70 mm Hg, heart rate 80 beats per minute, and respirations 12 breaths per minute. What is the most appropriate treatment for this patient? Intravenous ceftriaxone Intravenous fluids Oral ciprofloxacin Oral rehydration
Correct Answer ( D ) Explanation: Salmonellosis is a gastroenteritis caused by Salmonella enterica, a nontyphoidal serotype of Salmonella. It is caused by ingestion of contaminated water or food, particularly chicken and uncooked eggs. Symptoms appear about 8-48 hours after ingestion, and present as fever, nausea, vomiting, crampy abdominal pain, and bloody or "pea soup" diarrhea. Diagnosis may be made with a stool culture, but is not always necessary, as the illness is usually self-limiting. The best treatment for salmonellosis is supportive care and focuses on fluid replacement to combat dehydration. For this patient, who denies vomiting and does not show altered vital signs, oral rehydration is most appropriate. Antibiotic treatment with ciprofloxacin or ceftriaxone may be considered for certain cases (e.g. severe illness, immunocompromised host, such as a patient with sickle cell disease).
A 27-year-old homosexual man presents to your office with a complaint of flu-like symptoms. Physical exam reveals rash on both hands and diffuse lymphadenopathy. Upon further questioning, the patient indicates that he had a painless sore on his penis three weeks ago shortly after having unprotected intercourse with a new partner. After lab confirmation, which of the following is the most appropriate pharmacotherapy? Acyclovir Azithromycin Ceftriaxone Penicillin
Correct Answer ( D ) Explanation: Syphilis is an infection caused by the bacterium Treponema pallidum. The group most affected by primary and secondary syphilis in the United States is men who have sex with men. Patients with primary syphilis often remain untreated because the primary stage of the disease may be asymptomatic or the painless chancre goes unnoticed. Secondary syphilis infection classically presents as a rash on the palms and soles along with non-specific symptoms such as fever, malaise, headache, diffuse lymphadenopathy and anorexia. Penicillin is used to treat all stages of syphilis and no resistance has been reported, despite many decades of using this medication.
A 17-year-old girl with a history of asthma and seasonal allergies presents to her pediatrician with complaints of a burning mouth and tongue. On physical exam, her tongue and buccal mucosa are coated in creamy, white patches. The patches can be scraped away to reveal an erythematous base. Which of the following is the most likely diagnosis? Apthous ulcers Oral leukoplakia Oral squamous cell carcinoma Oropharyngeal candidiasis
Correct Answer ( D ) Explanation: The girl in this case most likely has oropharyngeal candidiasis. Oropharyngeal candidiasis, or thrush, is a Candida infection of the buccal mucosa, tongue, or pharynx. The most common cause is Candida albicans. Oropharyngeal candidiasis occurs when normal host immunity or host flora is disrupted. Oropharyngeal candidiasis is most commonly seen in infants, denture wearers, patients recently treated with antibiotics, patients who have received radiation therapy, and in patients who are immunocompromised. Oral candidiasis is one of the most common initial manifestations of human immunodeficiency virus (HIV) infection. The most common presenting symptoms are painful mouth and tongue, loss of taste, a cottony mouth feeling, and dysphagia. Infants may present with feeding difficulties and failure to thrive. Immunocompromised patients often have concurrent esophageal candidiasis, which can cause dysphagia and odynophagia. Physical exam reveals white or creamy patches and diffuse erythema. Lesions can be scraped away to reveal an inflamed base that is painful can bleed. Diagnosis can be confirmed by performing a Gram stain or potassium hydroxide preparation on the scrapings, which will show budding yeast and pseudohyphae. In HIV-negative patients, first-line treatment options include clotrimazole troches or nystatin swish and swallow. Topical therapy with clotrimazole troches or nystatin is recommended for HIV-positive patients with mild disease. Oral therapy with fluconazole is recommended for HIV-positive patients with moderate to severe disease or in patients with advanced immunosuppression (CD4 < 100 cells/microL).
Which of the following tick-borne illnesses is most associated with skin ulcers and lymphadenopathy? Babesiosis Colorado tick fever Lyme disease Tularemia
Correct Answer ( D ) Explanation: The major tick-borne diseases include Rocky Mountain spotted fever (RMSF), Lyme disease, ehrlichiosis, babesiosis and tularemia. Tularemia is caused by Francisella tularensis and is transmitted to humans either by tick bites or handling of infected animals (rabbits and rodents). Each of these diseases begins with non-specific viral-syndrome like symptoms including fever, myalgias, arthralgias and headache. Clinicians may be alerted to the presence of a tick-borne illness if a history of exposure (hiking in the woods, tick bite) are elicited. However, up to 50% of patients with a tick-borne illness do not recall a tick bite. Additionally, if labs are obtained, there are some common findings that would differentiate from a viral illness. Thrombocytopenia is often seen in RMSF, ehrlichiosis, tularemia and babesiosis. A mild elevation in hepatic transaminases is associated with RMSF, Lyme disease, ehrlichiosis, tularemia and babesiosis. Tularemia is associated with ulceroglandular disease.
Which of the following organs is involved in the life cycle of malaria in humans? Brain Heart Kidneys Liver
Correct Answer ( D ) Explanation: The malaria cycle is a complex one involving both the Anopheles mosquito and humans. When an Anopheles mosquito bites a human, sporozoites are transmitted into the human bloodstream. These sporozoites migrate to the liver where they invade hepatocytes, then divide and form multinucleated schizonts. Clinical symptoms are absent during this stage. The schizonts then rupture, releasing merozoites into circulating blood where they invade previously healthy red blood cells. Merozoites mature in human red blood cells, then are ingested by the Anopheles mosquito via mosquito bite. Further maturation from merozoite to sporozoite occurs in the mosquito's midgut, then migration to the mosquito's salivary glands occurs. The cycle is completed by transmission to another host when the mosquito with mature malaria sporozoites bites another human.
A 32-year-old man presents to the county health department with complaints of a painless sore on his penis. He admits to having unprotected sexual intercourse 2 weeks ago. Physical exam reveals a single 2 cm nontender ulcer with a raised, indurated margin on the shaft of his penis. Which of the following is the most likely causative organism? Haemophilus ducreyi Herpes simplex virus Neisseria gonorrhoeae Treponema pallidum
Correct Answer ( D ) Explanation: The patient most likely has syphilis, a sexually transmitted infection caused by Treponema pallidum. The majority of syphilis cases are sexually acquired, however vertical transmission can occur. Patients who are at high risk for syphilis include men who have sex with men, inmates, patients who have multiple sexual partners, and patients with other sexually transmitted diseases. Syphilis can be classified into four stages: primary, secondary, latent, and tertiary. Primary syphilis is characterized by a round, painless ulcer, known as a chancre. The chancre typically appears 2-3 weeks after exposure and heals within a few weeks. Approximately 25% of patients with untreated primary syphilis develop secondary syphilis. Secondary syphilis presents with a rash, fever, headache, malaise, anorexia, and diffuse lymphadenopathy. Like primary syphilis, secondary syphilis usually resolves spontaneously. Latent syphilis indicates the patient is still infected with T. pallidum, but is asymptomatic. Tertiary syphilis develops 1-30 years after initial infection. The most common complications of tertiary syphilis include neurosyphilis, cardiovascular syphilis (aortitis), and gummatous syphilis. Diagnostic testing can be performed through non-treponemal tests, treponemal tests, and direct visualization. Nontreponemal tests, such as Venereal Disease Research Laboratory (VDRL) or Rapid Plasma Reagin (RPR), are commonly used as screening methods due to cost and ease of use. Positive nontreponemal tests require confirmation with treponemal tests, which are based on antibodies against specific treponemal antigens. Darkfield microscopy, although quickest and most direct, requires specialized equipment and prompt examination of the specimen. Under dark field microscopy, T. pallidum appear as thin, delicate corkscrews with tightly round spirals. Cerebrospinal fluid examination is the only method for diagnosing asymptomatic neurosyphilis. A one time single dose of intramuscular penicillin G is recommended treatment for early syphilis. Late stages of syphilis require three doses. All cases of syphilis should be reported to the Center for Disease Control.
A 26-year-old woman presents two days after an operation for recurrent sinusitis. Her husband states that she has been confused since she got "the flu" yesterday. Her vitals are temperature 39.5°C, HR 115, BP 95/70, and oxygen saturation is 99% on room air. On exam, she is disoriented and has a diffusely hyperemic, blanching rash. She has a surgical dressing covering her nose. What is the next step in management? Administer broad-spectrum antibiotics Obtain a CT scan of the sinuses Perform a wound culture Remove the surgical dressing
Correct Answer ( D ) Explanation: The surgical dressing must be removed to ensure there is no nasal packing or other foreign body present that could serve as a precipitant of toxic shock syndrome (fever, hypotension, diffuse erythroderma, multisystem organ dysfunction). Toxic shock syndrome is commonly associated with postsurgical dressings as well as vaginal foreign bodies (classically, extended-use tampons). Toxic shock syndrome toxin-1 (TSST-1) producing strains of S. aureus cause the infection, with the toxin serving as a superantigen that leads to overstimulation of T-lymphocytes and subsequent massive, unregulated cytokine release. Patients often report a prodrome of flu-like symptoms including headache, myalgias, vomiting, and diarrhea.
A 58-year-old man presents to the ED with complaints of severe fever and chills, a diffuse headache, abdominal cramping, nausea and vomiting, and general weakness with lethargy. He returned from a lengthy business trip to Central America six days ago and has been experiencing such symptoms every three days. He notes that he had some generalized irregular fever while in Central America, but did not seek help at that time. His blood pressure is 148/72 mm Hg, respiratory rate 24, heart rate 122, oxygen saturation of 96% on 2L NC, and temperature 40.6°C. On exam, you note scleral icterus. Physical exam is unremarkable, with guaiac negative stool. Lab results reveal a hemoglobin of 8 g/dL, platelets 175/µL, LDH 800 U/L, and indirect bilirubin 2.5 mg/dL. Which of the following is the most likely cause of this patient's symptoms? Babesiosis Chagas disease Dengue fever Malaria
Correct Answer ( D ) Explanation: There are four known types of malaria: Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. Although P. vivax is the most common form, P. falciparum leads to the most virulent disease, causing most cases of severe malaria and most malaria-related deaths. Because of its ubiquitous presence in much of the world, malaria should be considered in any patient with severe fevers and chills who reports recent travel to an endemic region. Classically, malaria begins with a flu-like prodrome that progresses to cyclical episodes of chills followed by fever, each lasting about two hours. These episodes recur every three days with P. vivax and P. ovale and every four days for P. falciparum and P. malariae. These episodes are associated with a hemolytic anemia, as identified in this patient by scleral icterus, low hemoglobin, elevated LDH, and indirect bilirubin. Identifying Plasmodial parasites on Giemsa-stained thick and thin smears makes the definitive diagnosis.
An 18-year-old man presents to the ED near where he resides in southern Missouri, complaining of fever and shortness of breath for two weeks. His temperature is 37.5°C, heart rate 107, blood pressure 115/76 mm Hg, respiratory rate 22 breaths per minute, and his oxygen saturation on room air is 94%. He is a construction worker whose hobbies include hiking, caving, and hunting. A chest radiograph shows multiple granulomas and hilar adenopathy. Which of the following organisms is most likely responsible for his presentation? Blastomyces dermatitides Candida glabrata Coccidioides immitis Histoplasma capsulatum Taenia saginata
Correct Answer ( D ) Explanation: This man has multiple factors in his history that are consistent with a fungal pulmonary infection caused by histoplasmosis. He lives in southern Missouri, the correct region; he also works in construction and has a hobby of caving. Histoplasmosis is typically linked to contact with bird or bat droppings or exposure to construction sites. It is found almost exclusively in the Mississippi and Ohio River valleys. The disseminated form of this illness can be asymptomatic or can cause a pneumonia-like illness. Findings on chest radiograph can be variable but often include hilar adenopathy.
A 23-year-old man presents with a sore on penis. He had unprotected sex two weeks ago. Physical exam reveals a painless, round ulcer on the shaft of his penis and bilateral inguinal lymphadenopathy. Which of the following is the most likely causative agent? Haemophilus ducreyi Herpes simplex virus Mycoplasma genitalium Treponema pallidum
Correct Answer ( D ) Explanation: This man most likely has syphilis, which is caused by the bacterium Treponema pallidum. Almost all cases of syphilis are acquired through sexual contact. Syphilis is typically classified into 4 stages: primary early, secondary, latent, and tertiary. Syphilis can only be transmitted during the primary and secondary stages, when there are open lesions present. In the United States, the majority of syphilis cases occur in men who have sex with men. The average incubation period is three weeks. Primary syphilis is characterized by a painless ulcer, called a chancre, which is 1-2 cm in diameter and has raised, indurated margins. These lesions are typically located on the genitalia, but can occur at any site of inoculation. Without treatment, the chancre usually spontaneously resolves within 3-6 weeks. Secondary syphilis develops in about one-quarter of patients with untreated primary syphilis. Secondary syphilis classically presents with a diffuse macular or papular rash that does not spare the palms and soles. Dark field microscopy is the best method for diagnosing the chancre of primary syphilis. Serologic testing is primarily used for secondary syphilis. A single dose of penicillin G intramuscularly is the treatment of choice for primary and secondary syphilis. In penicillin allergic, non-pregnant patients, doxycycline is recommended as the first-line treatment.
A 67-year-old man presents to his physician's office with a 3-day history of progressive right-sided facial weakness. He denies upper and lower extremity weakness, trouble speaking, fever, and dizziness. On exam, the man has right-sided facial droop and vesicular eruptions on the right side of his right external auditory canal. Which of the following is the most likely diagnosis? Guillain-Barré syndrome Ischemic stroke Myasthenia gravis Ramsay Hunt syndrome
Correct Answer ( D ) Explanation: This man, with ipsilateral facial paralysis and vesicles in the auricle, most likely has Ramsay Hunt syndrome. The varicella zoster virus causes two distinct clinical syndromes. Prior to the widespread use of the varicella vaccine, the primary infection was a common pediatric, highly contagious disease, characterized by a pruritic, vesicular rash. After the primary infection, the varicella virus remains latent in the neurons and dorsal root ganglia. Herpes zoster occurs when the virus is reactivated, resulting in a rash localized to a dermatome. Herpes zoster has several serious complications that clinicians should be aware of. Immunocompromised patients have an increased risk of complications. Involvement of the trigeminal nerve can lead a serious vision-threatening condition called herpes zoster ophthalmicus. Vesicular lesions on the nose (Hutchinson's sign) are associated with high risk of ocular involvement. Early diagnosis is critical to avoid progressive involvement of the corneal and possible vision loss. Ramsay Hunt syndrome is reactivation along cranial nerve VII. Patients with Ramsay Hunt syndrome typically present with the triad of facial paralysis, ear pain, and a vesicular eruption in the auricle and ear canal. Other serious complications include acute retinal necrosis, superimposed bacterial infection, aseptic meningitis, transverse myelitis, and encephalitis. A careful neurologic exam should be performed to rule out other complications and other causes of unilateral facial weakness. Physical exam should also involve thorough testing of the trigeminal nerve to rule out ocular involvement. Patients with ocular involvement should have an urgent referral to an ophthalmologist and be started on antiviral therapy. Corticosteroids and oral antivirals are the treatment of choice for Ramsay Hunt syndrome. Patients with Guillain-Barré syndrome (A) typically present 2-4 weeks after a viral or gastrointestinal illness with progressive muscle weakness. The weakness and paralysis of Guillain-Barré syndrome is classically ascending and symmetrical. Ventilatory failure may occur as the paralysis ascends. Patients with Guillain-Barré syndrome should be admitted to the hospital for monitoring of potential respiratory failure.
A 33-year-old woman with a history of HIV presents after a generalized tonic clonic seizure. A CT scan is performed of the head as shown above. Which of the following treatments should most likely be initiated? Albendazole Ampicillin Ceftriaxone Pyrimethamine and sulfadiazine
Correct Answer ( D ) Explanation: This patient presents with toxoplasmosis encephalitis and should be treated with pyrimethamine and sulfadiazine. Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii. Cats are the primary reservoir for human infection. Infection is mild in healthy patients and will often present with flu like symptoms. However, in those with immunocompromise including HIV/AIDS, the disease can be more severe and be complicated by encephalitis. Encephalitis from toxoplasmosis presents with headache, nausea, vomiting, fever, altered mental status, focal neurologic deficitis and seizure activity. In any patient with a history of HIV and a new seizure, a CT scan of the head should be obtained. Although the disease more commonly affects patients with AIDS, it can also be seen in patients with HIV. The diagnosis of toxoplasmosis encephalitis can be made based on the findings with a contrast CT scan. CT scan will reveal multiple ring-enhancing lesions in 70-80% of cases. The treatment of toxoplasmosis encephalitis is with pyrimethamine and sulfadiazine. Folinic acid should be supplemented as well.
A 26-year-old woman with a known history of AIDS presents to the ED for strange behavior, according to her boyfriend. Reportedly, she complained of a headache for a few days prior and then began acting bizarrely. In the ED she has a temperature of 38.5°C. Neurological examination is remarkable for word-finding difficulties accompanied by episodes of clanging and echolalia, along with decreased attention span, recall, and consolidation. A contrast CT scan of the brain reveals multiple ring-enhancing lesions without evidence of midline shift. Which of the following is the most appropriate next step in management? Consult neurosurgery for a brain biopsy Obtain an MRI Treat with dexamethasone Treat with pyrimethamine and sulfadiazine Treat with trimethoprim-sulfamethoxazole
Correct Answer ( D ) Explanation: This patient with AIDS and altered mental status most likely has cerebral toxoplasmosis, the most common cause of focal encephalitis in patients with AIDS. It is often accompanied by fever, headache, altered mentation, focal neurologic deficits, and seizures. It is caused by the protozoa Toxoplasma gondii. The initial diagnosis is based on history, physical, and head CT scan. The appearance of multiple ring-enhancing lesions on contrast-enhanced head CT scan is pathognomonic. Treatment should be initiated with pyrimethamine and sulfadiazine. Some regimens also include folinic acid.
A 15-year-old girl presents for increased urinary frequency and vaginal discharge. On pelvic exam you note frothy yellow discharge and a "strawberry cervix." Which of the following is the most likely diagnosis? Bacterial vaginosis Candidiasis Chlamydia Trichomoniasis
Correct Answer ( D ) Explanation: Trichomoniasis is one of the most common sexually transmitted infections. The flagellated organism, Trichomonas vaginalis, causes it. Symptoms in women include vaginal burning and itching, abnormal vaginal odor, and dyspareunia. Although men can contract the disease, they are often asymptomatic. On exam the vulva may be edematous, excoriated, and erythematous while the vagina and cervix may be red and inflamed. The characteristic finding on exam is a "strawberry cervix" which is caused by friable mucosa with punctate hemorrhagic ulcerations. Microscopy of vaginal secretions reveals flagellated organisms. Treatment is with metronidazole. Partners should also be treated.
Rapid Review Dengue Fever
Dengue Fever Patient with a history of recent travel to tropical regions Complaining of "breakbone fever" - high fever with a biphasic pattern, myalgias, and backache Labs will show thrombocytopenia, elevated LFTs and leukopenia Most commonly caused by Aedes aegypti mosquito Treatment is supportive
Rapid Review Disseminated Gonococcal Infection
Disseminated Gonococcal Infection Fever, migratory arthritis, rash Erythematous or hemorrhagic papules → pustules/vesicles with erythematous halos Tenosynovitis
Rapid Review Gonococcal Urethritis
Gonococcal Urethritis Patient will be complaining of purulent uretheral discharge and dysuria Labs will show gram-negative diplococci Diagnosis is made by: Gold standard - culture on Thayer-Martin media; PCR test is both sensitive and specific Most commonly caused by Neisseria gonorrhoeae Treatment is Ceftriaxone 250 mg IM AND Azithromycin 1 g PO or doxycycline 100 mg BID x 7 days
Rapid Review Histoplasmosis
Histoplasmosis Patient with a history of travel to Ohio/Mississippi river valleys and exposure to bird/bat droppings X-ray will show solitary pulmonary calcification, hilar and mediastinal adenopathy Diagnosis is made by culture Treatment is itraconazole or amphotericin B
Rapid Review Infectious Mononucleosis
Infectious Mononucleosis Patient will be complaining of low-grade fever, headache, malaise, severe fatigue PE will show mildly tender lymphadenopathy involving the posterior cervical chain, hepatosplenomegaly Diagnosis is made by heterophile antibody test (monospot test), generalized maculopapular rash following administration of amoxicillin Most commonly caused by Epstein-Barr virus Treatment is self-limiting, refrain from contact sports for four weeks post-infection
Rapid Review Lyme Disease
Lyme Disease Patient with a history of being in the woods hiking or camping Complaining of: Stage I: erythema migrans (pathognomonic), viral-like syndrome (fever, fatigue, malaise, myalgia, headache) Stage II: arthritis, myocarditis, bilateral Bell's palsy Stage III: chronic arthritis, chronic encephalopathy PE will show slightly raised red lesion with central clearing, erythema migrans (bulls-eye) rash Most commonly caused by Borrelia burgdorferi carried by Ixodes tick Treatment is doxycycline. Kids/pregnant - amoxicillin Comments: Bilateral facial nerve palsy is virtually pathognomonic for Lyme disease
Rapid Review Malaria
Malaria P. falciparum (deadliest), P. ovale, P. vivax, P. malariae P. ovale, P. vivax: hepatic phase Anopheles mosquito Immigrant, traveler Irregular fevers, diaphoresis P. falciparum: cerebral malaria, Blackwater fever Uncomplicated, no resistance areas Rx: chloroquine Complicated, P. falciparum rx: artesunate or quinidine + doxycycline
Rapid Review Measles (Rubeola):
Measles (Rubeola): Patient will be an unvaccinated young child With a history of a maculopapular rash that started on head and spreads toward feet Complaining of high fever, cough, conjunctivitis, coryza PE will show red spots with blue/white center on buccal mucosa (Koplik spots) Diagnosis is made clinically Treatment is supportive care
Rapid Review Meningococcemia:
Meningococcemia: Patient will be a military recruit or student Complaining of fever, HA, arthralgias, rash PE will show petechiae, skin lesions with gray necrotic centers Diagnosis is made clinically and can be confirmed by blood cultures and gram stain, as well as lumbar puncture Most commonly caused by Neisseria meningitidis, an aerobic, gram-negative diplococcus Treatment is ceftriaxone and vancomycin Comments: Waterhouse-Friderichsen syndrome: bilateral adrenal hemorrhage + meningococcemia
Rapid Review Myocarditis
Myocarditis Leads to dilated cardiomyopathy, CHF Sudden death in young adults Idiopathic > viral (Parvovirus 19) Viral prodrome Positive troponin ST-segment elevation ECHO shows global hypokinesis Supportive management, possible transplant
Rapid Review Necrotizing Fasciitis
Necrotizing Fasciitis Type 1: polymicrobial - abdomen and perineum Type 2: GAS infection - extremity Pain out of proportion to exam Systemic signs of infection Cellulitis turns dusky blue with bullae/vesicles Radiograph: subcutaenous emphyesma Emergent surgical debridement
Rapid Review Neurosyphilis
Neurosyphilis Tertiary syphilis Occurs years after primary infection Personality changes, neurologic deficits CSF-VDRL Co-infection with HIV Intravenous penicillin
Rapid Review Rocky Mountain spotted fever (RMSF)
Rocky Mountain spotted fever (RMSF) Patient with a history of recently being in the woods hiking or camping Complaining of abrupt onset of severe headache, photophobia, vomiting, diarrhea, and myalgia PE will show maculopapular eruption on the palms and soles Diagnosis is made by skin biopsy Most commonly caused by Rickettsia rickettsia Treatment is ALWAYS doxycycline, even in children
Rapid Review Rocky Mountain spotted fever (RMSF)
Rocky Mountain spotted fever (RMSF) Patient with a history of recently in the woods hiking or camping Complaining of abrupt onset of severe headache, photophobia, vomiting, diarrhea, and myalgia PE will show maculopapular eruption on the palms and soles Diagnosis is made by skin biopsy Most commonly caused by Rickettsia rickettsia Treatment is ALWAYS doxycycline, even in children
Rapid Review Salmonellosis
Salmonellosis Patient with a history of eating poultry, meat, or eggs Complaining of fever, bloody diarrhea, and abdominal cramps Labs will show fecal WBCs Comments: common cause of osteomyelitis in children with sickle cell disease
Rapid Review Secondary Syphilis
Secondary Syphilis Patient will be sexually active With a history of painless chancre 5 - 8 weeks ago Complaining of a rash on palms and soles PE will show lymphadenopathy, brownish-red macules and papules, condyloma lata (flat, greyish plaques) Diagnosis is made by VDRL and RPR Most commonly caused by Treponema pallidum Treatment is IM benzathine penicillin G x 1 dose
Rapid Review Shigellosis
Shigellosis Patient will be complaining of fever, bloody, mucoid diarrhea and seizures (more common in children) Labs will show fecal RBCs and WBCs Treatment is ciprofloxacin for the adult patient Complications: HUS, Reiters syndrome
Rapid Review Spontaneous Bacterial Peritonitis
Spontaneous Bacterial Peritonitis Patient will have a history of chronic liver disease or cirrhosis Complaining of fever, chills, and abdominal pain PE will show ascites, shifting dullness Labs will show PMNs > 250, WBC >1,000, pH <7.34 Diagnosis is made by analysis of the ascitic fluid Most commonly caused by E. coli, Streptococcus spp Treatment is immediate IV antibiotics (third-generation cephalosporin)
Rapid Review Syphilis
Syphilis Primary: painless chancre Secondary: lymphadenopathy, condyloma lata, rash on palms/soles Tertiary: gummas VDRL and RPR positive 4-6 weeks after infection Primary/secondary: IM benzathine penicillin G x 1 dose Tertiary: IM benzathine penicillin G qwk x 3 weeks
Rapid Review Toxoplasmosis
Toxoplasmosis Patient will be HIV positive Complaining of focal neurologic deficits CT will show multiple ring-enhancing lesions Treatment is pyrimethamine, sulfadiazine, folinic acid
Rapid Review Trichomoniasis
Trichomoniasis Patient will be a woman complaining of malodorous vaginal discharge PE will show frothy, green/yellow discharge, "Strawberry cervix" Labs will show pH >5, flagellated, motile, pear shaped Diagnosis is made by wet mount Most commonly caused by Trichomonas vaginalis Treatment is metronidazole
Rapid Review Tularemia
Tularemia Patient with a history of handling rabbits Complaining of ulcer at wound site PE will show ulceroglandular findings, conjunctivitis, pneumonia Most commonly caused by Francisella tularensis Treatment is streptomycin
Rapid Review Varicella
Varicella Viral prodrome → maculopapular rash → clear vesicles on an erythematous base ("dew drop rash on a rose petal") Lesions occur in crops Contagious 5 days before and after vesicles Multiple stages of lesions present Treatment: <12: supportive care >12: acyclovir Immunocompromised: IV acyclovir
