Chapter 22 - Skin Infections

Match the viral disease name to the correct image. 1. Painful rash in one condensed area 2. Small red bumps with some small blisters 3. Rash along baby's back, looks like red freckles

!. Shingles 2. Chickenpox 3. Measles

Place the steps of the disease pathway in the correct order to test your understanding of the pathogenesis of measles. Not all labels are used.

1. Airborne rubeola virus infects upper respiratory tract, then nearby lymph nodes. 2. Virus enters the bloodstream and is carried to all parts of the body, including brain, lungs, and skin. 3. Skin cells infected with rubeola virus are attacked by cytotoxic T cells, causing rash. 4. Virus replication in lungs can cause pneumonia; brain can also be infected. 5. Secondary infection of ears and lungs common. 6. Transmission is by respiratory secretions.

Match the correct type of normal skin microbiota with the appropriate descriptions. Not all labels are used. 1. Gram-positive, facultatively anaerobic cocci arranged in clusters 2. Variably shaped, non-motile rods of the Cutibacterium and Corynebacterium genera 3. Small yeasts of the genus Malassezia that require oily substances for growth

1. Staphylococci 2. Diphtheroids 3. Fungi

Disease Summary Activity: Match the bacteria to the correct description of the bacterial skin disease it causes. Not all labels are used. 1. Causative agent colonizes nostrils and moist skin; frequently antibiotic resistant; infections include folliculitis, furuncles and carbuncles 2. Most common during puberty, probably due to excess sebum secretion 3. Spread by ticks; characterized by rash that spreads and becomes hemorrhagic 4. Causes disease characterized by blisters that break and are replaced by oozing yellow crusts 5. Causes disease characterized by peeling of the epidermis; mostly found in infants and newborns 6. Spread by ticks; characterized by "bull's eye rash"; later symptoms include arthritis, damage to heart and brain

1. Staphylococcus aureus 2. Cutibacterium acnes 3. Rickettsia rickettsii 4. Stephtococcus pyogenes; Staphylococcus aureus 5. Exfoliatin-producing Staphylococcus aureus 6. Borrelia burgdorferi

Match the correct label with the diseases shown. Not all labels are used. 1. Wart on hand 2. Rash/dry skin on toes 3. Dark indented mark on skin 4. Rash on baby's genitals

1. Wart - papillomaviruses 2. Tinea pedis - Trichophyton species 3. Cutaneous anthrax - Bacillus anthracis 4. Diaper rash - Candida albicans

Please rank the hair follicle infections from least serious to most serious. 1. Cabuncle 2. Folliculitis 3. Furuncle

2, 3, 1

Examine the status of MRSA infections in the United States today by completing each sentence, then arrange the sentences in a logical sequence. 1. In 2004, MRSA infections began to appear in individuals with no history of hospitalization; these were classified as ____________ MRSA. 2. These are strains of S. aureus that are resistant to ____________ derivatives, and are commonly found associated with nosocomial infections called ____________ MRSA. 3. ____________ stands for ____________ -resistant Staphylococcus aureus. 4. CA-MRSA strains are more susceptible to a wider array of antibiotics, where HA-MRSA strains often require treatment with ____________ due to their drug resistance.

3. MRSA; methicillin 2. penicillin; healthcare-associated 1. community-acquired 4. vancomycin

Which of the following are transmitted via the respiratory route? A. Rubella virus B. Rubeola virus C. Varicella-zoster virus D. Papillomaviruses E. Parvovirus B-19

A, B, C, E

All of the following diseases are characterized by the development of a rash. Which are NOT caused by herpesviruses? A. Rubeola B. Warts C. Fifth disease D. Chickenpox E. Scarlet fever F. Shingles G. Roseola H. Rubella

A, B, C, E, H

Select all the statements that describe the function of the skin. A. It prevents the entry of microbes. B. It regulates body temperature. C. Epidermal cells produce bacteriocins that kill potential pathogens. D. It prevents dehydration. E. Sloughing of the epidermis helps remove potential pathogens. F. It plays a role in proper immune system function. G. It contains fat that is an energy reserve.

A, B, D, E, F

Potential complications associated with measles and the measles vaccine include A. earaches B. bacterial pneumonia C. birth defects D. autism E. subacute sclerosing panencephalitis F. encephalitis

A, B, E, F

Identify which of the following organisms are examples of normal skin microbiota that can cause opportunistic infections. A. Staphylococcus aureus B. Malassezia furfur C. Borrelia burgdorferi D. Papillomaviruses E. Rickettsia rickettsii F. Candida albicans G. Cutibacterium acnes H. Varicella-zoster virus

A, B, F, G

Diaper rash may be caused by A. Candida albicans. B. Malassezia furfur. C. Microsporum species. D. Trichophyton species. E. All the choices are correct.

A. Candida albicans.

An important diagnostic sign of measles is A. Koplik's spots B. giant cells C. fever D. swollen lymph nodes E. red, weepy eyes

A. Koplik's spots

Many childhood diseases caused by viral infections of the upper respiratory tract can usually be diagnosed by A. inspection of the rash B. the type of cough C. the type of fever D. the incubation period E. the gender of the patient

A. inspection of the rash

The preferred habitat of S. aureus is the A. nasal chamber B. throat C. urethra D. bladder E. meninges

A. nasal chamber

Warts are caused by A. papillomaviruses B. parvovirus C. adenoviruses D. herpes virus E. coronavirus

A. papillomaviruses

The main vector(s) of Rocky Mountain spotted fever in the western United States is/are ______. A. ticks B. bats AND humans C. humans D. mosquitoes AND ticks E. fleas AND mites

A. ticks

After being bitten by an infected tick, transfer of the rickettsial organism occurs A. within 4-10 hours B. within 20 minutes C. within 5 minutes D. immediately E. after 7 days

A. within 4-10 hours

Please place the statements about acne and hair follicle infections into the appropriate columns.

Acne: 1. May be related to puberty 2. Caused by Cutibacterium acnes 3. Caused by increased sebum production 4. Causative organism an obligate anaerobe 5. Characterized by enlarged sebaceous glands Hair follicle infections: 1. Caused by Staphylococcus aureus 2. May cause life-threatening disease 3. Causative agent has many virulence factors 4. Treatment may require minor surgery 5. Causative agent often antibiotic resistant

Which is considered the most serious staphylococcal skin infection? A. Tinea versicolor B. Carbuncles C. Folliculitis D. Furuncles E. Acne

B. Carbuncles

Which of the following normal skin microbiota is a small yeast? A. Staphylococci B. Malassezia species C. Diphtheroids D. Candida species E. Cutibacterium species

B. Malassezia species

Which of the following is/are transmitted by ticks? A. Cutaneous anthrax B. Rocky Mountain spotted fever C. Staphylococcal scalded skin syndrome D. Impetigo E. Chickenpox

B. Rocky Mountain spotted fever

Why is staphylococcal scalded skin syndrome sometimes fatal? A. The first line of defense is compromised, putting the patient at risk secondary bacterial infection. B. The first line of defense is compromised, putting the patient at risk of both dehydration and secondary bacterial infection. C. The causative organism is Gram-negative and may cause endotoxic shock. D. Exfoliatin can bind to cardiac cells, causing disruption of the heart rhythm and heart failure. E. The first line of defense is compromised, putting the patient at risk of severe dehydration.

B. The first line of defense is compromised, putting the patient at risk of both dehydration and secondary bacterial infection.

Why is the immunization for rubella important for both boys and girls? A. As this is a sexually-transmitted disease, vaccinating girls AND boys early in their lives prevents the spread of the disease in adulthood. B. We want to achieve herd immunity, and there's no reason why only girls would be infected by this virus. By vaccinating the entire population, we achieve a higher degree of herd immunity than is possible by vaccinating only girls. C. Only boys get this disease, and one of the common complications of it is sterility, so they should be vaccinated against this virus. D. While this disease is quite very symptomatic in girls, it is completely asymptomatic in boys. Boys can be carriers and transmit it easily to girls without realizing it. This can lead to large-scale and dangerous outbreaks in the female population. E. Although boys get this disease, it doesn't cause any health problems for them, so they do not need vaccination. If girls get the disease, it almost always leads to encephalitis, so they should be protected by vaccination.

B. We want to achieve herd immunity, and there's no reason why only girls would be infected by this virus. By vaccinating the entire population, we achieve a higher degree of herd immunity than is possible by vaccinating only girls.

Which of the following organisms is not normally found on the skin? A. Staphylococci B. Diphtheroids C. E. coli D. Malassezia species E. Staphylococci AND diphtheroids

C. E. coli

Which of the following is a pyoderma? A. Lyme disease B. Fifth disease C. Impetigo D. Chickenpox and shingles E. Staphylococcal scalded skin syndrome F. Rocky Mountain spotted fever

C. Impetigo

Rubella is a member of which virus family? A. Paramyxoviridae B. Herpesviridae C. Togaviridae D. Papovaviridae E. Retroviridae

C. Togaviridae

Treating hair follicle infections caused by Staphylococcus aureus can be challenging because A. the bacteria are facultative anaerobes and there are no medication available to kill such bacteria. B. the mycolic acids in the organism's cell wall prevent entry of antibiotics. C. many strains of the organism are resistant to multiple antibiotics. D. the organism colonizes in such high numbers that it is impossible to eliminate all cells. E. the organism is a virus and antibiotics do not affect viruses. F. the bacteria colonize hair follicles and antibiotics do not easily reach them.

C. many strains of the organism are resistant to multiple antibiotics.

The protein produced by S. aureus that interferes with phagocytosis is A. M protein B. collagen C. protein A D. capsular protein E. flagellin

C. protein A

The vector for RMSF is a(n) A. mosquito B. flea C. tick D. fly E. deer

C. tick

Which of the following statements about diphtheroids found on the skin are TRUE? A. They frequently cause carbuncles B. They are all acid-fast organisms C. An example is Malassezia furfur D. They are Gram-positive pleomorphic rods E. They are part of the skin normal microbiota F. An example is Cutibacterium (Proprionibacterium) acnes

D, E, F

How does coagulase help Staphylococcus aureus evade phagocytes? A. It coats the surface of the bacterial cells with collagen, a tissue binding protein. B. It coats the surface of bacterial cells with fibrin, a protein found in blood. C. It causes formation of small clots in capillaries, slowing progress of phagocytes to the infected area. D. It causes formation of small clots in capillaries, slowing progress of phagocytes to the infected area AND it coats the surface of bacterial cells with fibrin, a protein found in blood. E. It causes formation of small clots in capillaries, slowing progress of phagocytes to the infected area AND it coats the surface of the bacterial cells with collagen, a tissue binding protein.

D. It causes formation of small clots in capillaries, slowing progress of phagocytes to the infected area AND it coats the surface of bacterial cells with fibrin, a protein found in blood.

Which genus does not include skin-invading molds? A. Epidermophyton B. Microsporum C. Trichophyton D. Ixodes E. These are all skin molds

D. Ixodes

Which of the following is NOT true about diphtheroids? A. They are part of the normal microbiota of the skin. B. They are responsible for body odor. C. They include Cutibacterium acnes. D. They include Malassezia species. E. These are all true.

D. They include Malassezia species.

How do dermatophytes cause disease in humans? A. They infect the digestive tract. B. They infect the conjunctiva of the eyes. C. They infect the respiratory tract. D. They infect keratinized regions of the body. E. They infect the meninges.

D. They infect keratinized regions of the body.

The existence of extensive scalded skin syndrome does not indicate that Staphylococcus is growing in all the affected areas. Why not? A. This condition is caused by an exotoxin produced by certain strains of this microbe, and NOT directly by the microbe itself. B. This condition is caused by an endotoxin produced by certain strains of this microbe, and NOT directly by the microbe itself. C. This condition isn't caused by Staphylococcus at all. D. This microbe grows in the blood; endotoxins it releases are transported to the skin, where it causes the observed effect. E. Scalded skin occurs when a person eats exfoliatin-contaminated food, not by an infection.

D. This microbe grows in the blood; endotoxins it releases are transported to the skin, where it causes the observed effect.

A student complained of patches of scaly, lightened skin on his back. A skin scraping revealed the presence of both yeast and filamentous fungi. Based on this information, you can conclude that the student likely has ______ caused by ______. A. Tinea versicolor; Microsporum species B. Tinea corporis; Malassezia furfur C. Candida albicans; tinea corporis D. Tinea versicolor; Malassezia furfur E. Tinea corporis; Candida albicans

D. Tinea versicolor; Malassezia furfur

A common viral rash of childhood with the popular name chickenpox is also known as A. bariola B. rubella C. rubeola D. varicella-zoster E. salmonella

D. varicella-zoster

The secretions of the sweat and sebaceous glands provide ______ to the microbiota. A. water B. amino acids OR water C. lipids AND amino acids D. water AND lipids E. sebum OR amino acids

D. water AND lipids???

The antimicrobial aspect(s) of the skin is/are A. dryness B. saltiness C. acidity D. toxicity E. All of the choices are correct.

E. All of the choices are correct.

Why is it important to continue vaccinating children in the United States against measles, even though it is now a rare disease in the Western Hemisphere? A. A rare complication of measles is subacute sclerosing panencephalitis (SSPE) that is characterized by progressive brain degeneration, and generally results in death within 2 years. B. Measles that occurs during pregnancy increases the risk of miscarriage, premature labor, and low-birth-weight babies. C. Occasionally, the measles virus causes viral pneumonia, with rapid breathing, shortness of breath, and dusky skin color from lack of adequate O2 in the blood. D. Encephalitis is a rare but serious complication of measles that sometimes results in permanent brain damage, with mental disability, deafness, and epilepsy. E. All of these complications are reasons that the measles vaccine should be continued in the United States.

E. All of these complications are reasons that the measles vaccine should be continued in the United States.

What is the epidemiological significance of shingles? A. It shows that, as a latent viral infection, there is always a possible reservoir available to reinfect new susceptible individuals. B. It shows that we must always be vigilant against this deadly and highly infectious secondary infection in elderly and immunocompromised individuals. C. It shows that, as a chronic viral infection, individuals infected are always infectious to others around them, even when they do not show outward symptoms. D. It shows that our fight for long-term eradication of varicella zoster virus will be a long one, depending on immunizing all newly born individuals until all the people who had ever had contracted the illness have died. E. It shows that, as a latent viral infection, there is always a possible reservoir available to reinfect new susceptible individuals AND it shows that our fight for long-term eradication of varicella zoster virus will be a long one, depending on immunizing all newly born individuals until all the people who had ever contracted the illness have died.

E. It shows that, as a latent viral infection, there is always a possible reservoir available to reinfect new susceptible individuals AND it shows that our fight for long-term eradication of varicella zoster virus will be a long one, depending on immunizing all newly born individuals until all the people who had ever contracted the illness have died.

The MMRV vaccine is used to protect against A. measles, M. furfur, rabies, and varicella B. measles, mumps, rabies, and varicella C. mononucleosis, measles, German measles, and viruses D. measles, mange, rubella and varicella E. measles, mumps, German measles, chickenpox

E. measles, mumps, German measles, chickenpox

Reactivation of chickenpox is called A. shingles B. herpes zoster C. pneumonia D. exanthems E. shingles AND herpes zoster

E. shingles AND herpes zoster

True/False: A person who has never received the MMRV vaccine, and who is exposed to an individual with shingles, is at risk of contracting shingles as well.

False

True/False: All strains of Staphylococcus aureus can cause staphylococcus scalded skin syndrome.

False

Please classify the statements as describing Streptococcus pyogenes or Staphylococcus aureus and place them into the appropriate column.

Streptococcus pyogenes: 1. Morphology - chains of cocci 2. Growth characteristics - beta-hemolytic, catalase-negative, coagulase-negative 3. Virulence factors - cell wall contains protein G and M-protein; also produces streptolysins A and O 4. Diseases - impetigo, scarlet fever, puerperal fever, and toxic shock Staphylococcus aureus: 1. Morphology - clusters of cocci 2. Growth characteristics - golden colonies, hemolytic, catalase positive, coagulase positive 3. Virulence factors - cell wall contains protein A and some strains can also produce superantigens 4. Diseases - boils, scaled skin syndrome, impetigo, and toxic shock

True/False: Complications of measles may include pneumonia and encephalitis.

True