Gastrointestinal

What markers would indicate immunity to HBV via natural infection

(+) Anti-HBs (-) HBsag (+) IgG Anti-HBc

How would celiac disease present within first 2 years of life

- chronic diarrhea, failure to thrive, growth retardation, anorexia. (Short stature, weight loss) - if continued could develop ataxia and gross motor delay.

What are pathologic features of GERD in an infant

- failure to thrive (poor weight gain, dropping percentiles) , irritable - SANDIFIER SYNDROME: intermittent opisthotonic posturing. (Arching of back during and after feeding) - weight loss, apnea, resp symptoms Tx: thicken feeds (add oatmeal) , antacid therapy (PPI) are first steps - dont want to give if not necessary because PPI can cause pneumonia and diarrhea DX: 24 hour esophageal pH probe

How is pyloric stenosis diagnosed and what is treatment

1. Abdominal u/s - Thickened pyloric sphincter . Length > 14 mm , wall > 4 mm 2. Most accurate test - upper GI series : - string sign - thin column of barium leaking through tightened muscle - shoulder sign - filling defect in the Antrim due to prolapse of muscle inward - mushroom sign - hypertrophic pylorus against the duodenum - railroad track sign - excess mucosa in pyloric lumen TX: replace volume - IVF , replace electrolytes - especially potassium (but dont put potassium in fluids until confirm baby makes urine) - NGT - decompress gut - Surgery - pyloric myotomy - make sure electrolytes are normal before surgery - alkalosis can cause post op apnea.

What are 4 cardinal signs of strangulation with SBO (now complicated - go to OR)

1. Fever 2. Tachycardia 3. Leukocytosis 4. Localized abd tenderness

When is liver transplant firmly indicated in patients with ALF (acute liver failure)

1. Grade III or IV hepatic encephalopathy 2. PT > 100 seconds 3. Serum creatinine > 3.4

What are causes for immediate surgical intervention for SBO

1. Intestinal obstruction with clinical or hemodynamic instability 2. Fail to improve with conservative measures (after 48-72 hours) 3. Signs/symptoms of necrosis or ischemia

What is step up management for IBD

1. Start with mesalamine (5-ASA) If more than 3-4 exacerbations per year 2. Switch to azathioprine or 6-MP (mesalamine failed) 3. TNF inhibitors if: - refractory UC - fistula in CD ALWAYS check PPD first

8 years after diagnosis of ulcerative colitis what screening should take place

Surveillance colonoscopy - high risk for colon cancer. Especially if pancolitis or superimposed PSC. Repeat every 1-2 years. Colonic dysplasia on biopsy highly associated with progression to adenocarcinoma - may benefit from partial colectomy.

35 y/o man - 1 week history of excruciating pain during defecation - so severe, avoids defecating. Caliber of stool is unchanged but has had visible bright red blood on stool surface. PMH: chronic constipation. Rectal exam shows POSTERIOR mucosal tear of anus and a skin tag. In addition to stool softeners and sitz baths what is most appropriate next step.

Topical lidocaine and nifedipine Dx: Anal fissure. (Chronic fissures can have skin tag at distal end) - SENTINEL PILE. - longitudinal tear in anal canal distal to the dentate line - most common at posterior midline (90%) , anterior midline more common in women . - spasm of sphincter contribute to pain and creates tension around the wound, leading to chronic fissure - most related to chronic constipation with high anal pressure - patients have increased resting anal pressure d/t increased tone of internal sphincter muscle - have ischemia and ulceration to overlying site. INITIAL TREATMENT: - dietary modification (high-fiber diet, increased fluid intake) , stool softeners, sitz baths - increase blood flow to injured mucosa. - topical anesthetics (lidocaine) - topical vasodilators (nifedipine, NTG) to reduce pressure in, increase blood flow to, anal sphincter and facilitate healing. If chronic and conservative management fails - lateral internal sphinctereotomy

Malabsorption syndrome with history of living in tropical country (weight loss, steatorrhea, fat soluble vitamin deficiency

Tropical sprue Tx: doxycycline or TMPSMX x 6 months

Colorectal cancer with CNS malignancies (medulloblastoma, asytocytomas, ependymomas (FAP), gioblastoma (HNPCC)

Turcot's syndrome

Large bowel disease that presents with fever, bloody diarrhea and weight loss. Biopsy shows mucosal and submucosal inflammation only

Ulcerative colitis. M > F, ashkenazi Jews. Smoking decreases risk. Assoc: P-ANCA, PSC , toxic megacolon

Defect at linea alba covered by skin, sometimes contains bowel, umbilical cord inserts at apex of defect.

Umbilical hernia

Newborn/infant with Defect in linea alba, present with soft, non-tender bulge covered by skin that protrudes during coughing, crying or straining.

Umbilical hernia Management: - if small , typically close spontaneously - if large (>1.5 cm diameter) or patient with underlying medical problems, spontaneous closure less likely - surgery recommended around age 5 if hernia persistent or symptoms develop.

15 day old, bilious vomiting. No interest in feeding over past 24 hours. Passed meconium on first day of life and has had normal daily stools. Temp 36.7, bp 85/50, pulse 142 and resp 46. Dry mucous membranes. Abdomen soft and mildly distended. NGT placed for decompression and IVF started. AXR shows gasless abdomen - what is most appropriate next step in management.

Upper GI series (barium swallow) DX: Midgut volvulus - presents in neonate < 1 month with bilious vomiting. - primary predisposing factor for volvulus in kids is malrotation of midgut during early fetal development. Initially abdomen soft and not distended, ischemia and twisted bowel can eventually cause bloody stools, bowel perforation, abdominal distension and peritonitis. Signs of ischemia or systemic decompensation (shock) - emergent laparotomy Xray is usually nonspecific for midgut volvulus. - rarely the dx can be suspected if NGT terminates in abnormally placed duodenum. - if there is no evidence of free air, double bubble or distal obstruction - upper GI series (barium swallow) should be done - most accurate method to diagnose midgut malrotation with midgut volvulus. - finding of ligament of treitz on right side of abdomen - reflects malrotation - contrast in "Corkscrew pattern" indicates volvulus TX: surgery - if present, reduce volvulus, Ladd procedure is done - fix bowel in a non rotated position to reduce recurrent volvulus.

42 y/o woman, 4 weeks episodic upper abdominal pain - burning pain that waxes and wanes, assoc with nausea. Has awakened her at night also has bloating sensation after meals. Has had no dysphagia, regurgitation , weight loss or change in bowel habits. BMI 28, stool guaic is positive. What is most likely cause of her sx - came from india 20 years ago.

Urease-producing bacterial infection Dx: PUD d/t h pylori - patient has chronic intermittent epigastric pain and postprandial discomfort - dyspepsia. Hx of living in low income country with high prevalence of infection places her at high risk. DX: if no alarm symptoms - can do urea breath testing , stool antigen testing. If fails to improve after initial management (abx and PPI) then do endoscopy.

What is gold standard test for GERD:

24 hour pH monitoring.

Patient undergoes GI endoscopy for refractory GERD. Four hours after the procedure develops worsening substernal and left sided pain radiating to back and SOB. Pulse is 120, respirations 34. CXR - small ,left pleural effusion that wasnt present on CXR 2 weeks ago. EKG shows sinus tachy. What is most approriate test to confirm diagnosis:

Water-soluble contrast esophagogram DX: Acute esophageal rupture - acute chest pain, tachypnea, pleural effusion (left sided). May have subcutaneous emphysema. Endoscopy (iatrogenic) is mcc of esophageal rupture - contrast esophagogram is required to confirm diagnosis and demonstrate contrast extravasation through the tear - water soluble contrast is preferred (less inflammatory to tissues) Although a barium study has higher sensitivity and can be used if initial water soluble contrast is nondiagnostic. If perforation - primary closure of esophagus and drainage of mediastinum must be done to prevent development of mediastinitis also give abx.

Malabsorption syndrome with triad: dementia, arthralgias, opthalmoplegia

Whipple disease - abdominal distention, flatulence , steatorrhea. MYoclonus, migratory polyarthropathy, chronic cough, can also have myocardial / valvular involvement - chf or valve regurg. Skin pigmentation. DX: biopsy. - villous atrophy , can see PAS positive organism (t. Whippelli) gram positive. ORganisms fill macrophages , flood lamina propria and block lymphatics in small bowel macrophages, compress lacteals - CM cant transfer to enterocytes, causing fat malabsorption and steatorrhea. Tx: 2 weeks of IV ceftriaxone, then 1 year of TMP SMX or doxycycline

3 y/o found to have abdominal mass while being bathed. In usual state of health but noticed to have elevated bp (ex. 130/80)

Wilms Tumor (nephroblastoma) Second most common abdominal tumor - usual age 2-5 years. Arises from metanephros - precursor of renal parenchyma (metanephric blastema) Sx: - large unilateral flank mass that DOES NOT CROSS MIDLINE. - asymptomatic abdominal mass - unless invasive at diagnosis, will see increased BP (could have htn, anemia and hematuria) ASsoc: - WAGR - mutation of TSG on WT1 or WT2 - hemihypertrophy, aniridia, GU anomalies (cryptorchidism, ambiguous genitalia) - Beckwith-wiedemann - increased IGF1 - omphalocele, hemihypertrophy, hypoglycemia, umbilical hernia, also have increased risk for hepatoblastoma. DX: best initial test - u/s. Diagnose with CT scan to confirm with contrast. (See tumor in upper pole of kidney) - do CXR - mets to lung common TX: surgery then chemo and radiation

42 y/o with hx chrons disease - had partial ileal resection d/t stricture and had multiple surgeries to treat enterocutaneous fistula. Has received parenteral nutrition x weeks and recently restarted oral feeding. Nonobloody diarrhea but no fever or abdominal pain. Food doesn't taste the same as before. Has patchy alopecia and a pustular, crusting skin rash with scaling and erythema around mouth and on extremtiies. No abdominal tenderness and bowel sounds normal - what is most likely to improve patients condition

Zinc supplement. DX: Zinc deficiency - zinc is a trace mineral obtained from meat, nuts, fortified cereal. Need for gene transcription and cell division. Clinical manifestations of deficiency: - hypogonadism - impaired wound healing - impaired taste - immune dysfunction - alopecia - skin rash (erythematous pustules around body orifices (mouth) and on extremities. Absorbed in duodenum and jejunum - deficiency can be d/t malabsorption (chrons, celiac) , bowel resection, gastric bypass or poor nutrition. Patients that depend on TPN are at risk for trace mineral deficiency (Zinc, selenium, copper, chromium) d/t inadequate supplementation of parenteral intake. Comorbidities diarrhea and malabsorption further increase risk of trace mineral deficiency for patients on PN d/t excessive GI losses

What gene is affected in HNPCC, what are the associated cancers

AD - Mutation of DNA mismatch repair gene - microsatellite instability - Colorectal, Endometrium, OVarian

What gene is afffected in FAP

AD - TSH involved in cell adhesion, signal transduction and transcriptional activation.

What is the initial test of choice in patient with suspected toxic megacolon

Abdominal xray - need to exclude perforation NOTE: may suspect toxic megacolon in a patient with weeks of lower abdominal pain, bloody diarrhea and fecal urgency (undiagnosed IBD) who then presents with acute worsening with FEVER, ABDOMINAL DISTENSION, LEUKOCYTOSIS hypotension and tachycardia - If d/t severe colitis with massive colonic distention - toxic megacolon may be the first presentation of IBD and is potentially deadly ****** DX: AXR - > 6 cm dilation of right colon , systemic toxicity Tx: > 50% resolve with conservative mangement - NGT, bowel rest, steroids with broad spectrum abx or abx targeted at c diff.

27 y/o episodic abominable pain - in epigastrium and has gnawing quality. Wakes him up during night - relieved by glass of water and piece of bread. Has no associated vomiting or diarrhea has had some dark stools. No pmh. Smokes. Mild epigastric discomfort on deep palpation. What is most appropriate intervention for long term relief

Abx (amoxicillin and clarithromycin) and pantoprazole DX: Duodenal ulcer - epigastric pain , intermittent melena - pain of DU is worse on empty stomach and improves with food (unopposed gastric acid, alkaline fluid secretion into duodenum with food) - majority d/t h pylori or NSAIDS - since no history of NSAID use h pylori is most likely cause.

40 y/o male with dysphagia to solids and liquids, has to swallow standing upright, occasional regurg of undigested food , has had associated weight loss.

Achalasia - impaired peristalsis of distal esophagus with impaired relaxation of LES. Food and liquids are prevented from passing through LES until the hydrostatic pressure in the esophageal column is greater than the closing pressure of the sphincter - being in upright position increases the pressure in the esophagus. DX: Manometry (most sensitive) - increased LES resting pressure, incomplete LES relaxation, decreased peristalsis of distal esophagus Barium esophagram - smooth "bird beat" narrowing near LES Tx: upper endoscopy - r/o malignancy, laparoscopic myotomy or pneumatic balloon dilation, botulinum toxin injection, nitrates and CCB

37 y/o acute onset periumbilical abdominal pain assoc with nausea and vomiting. Hx of alcohol and IVDA - was diagnosed with infective endocarditis 4 days ago, being treated with IV vancomycin. In distress and restless - no signs of peritonitis. Febrile. AXR show now free air or obstruction. What is most likely diagnosis

Acute Mesenteric ischemia - embolism from cardiac valve vegetation (from I.E.) AMI is most commonly d/t abrupt arterial occlusion. - presents with sudden onset, severe, poorly localized (visceral) midabdominal pain with n/v. - in early-stage ischemia - physical exam is unremarkable, diffuse tenderness despite severe pain out of proportion to exam - if bowel infarcts - may have more focal abdominal tenderness (from local inflammation/infarction), peritoneal signs, rectal bleeding and sepsis. - Labs: leukocytosis, elevated Hb (hemoconcentration) , elevated amylase, metabolic acidosis (lactate)

Cause of fever, emesis and non bloody diarrhea in kids, lasts > 7 days and occurs year round ( assoc with warm weather)

Adenovirus

What is management for gastroschisis

After delivery - exposed bowel should be covered with sterile saline dressings and plastic wrap - minimize insensible fluid and heat losses. - NGT for gut decompression. - abx - surgical repair and can usually be accomplished in a single-stage closure

29 y/o man with chronic diarrhea, has had three operations for perianal fistula, havent healed, surgical wound now bigger and has multiple un healing fistulas

Anal fistula assoc with chrons disease. - the fistula wont heal unless you control chrons disease- DO NOT MANAGE THESE FISTULAS SURGICALLY. TX: drain with seton - put rubber band around the tract so it keeps draining then give medication for chrons. REmission with imuran, 6-MP if refractory cases - anti-TNF (infliximab)

65 y/o woman - 3-4 episodes of dark maroon colored stool over last 2 weeks, normal bowel movements. No pain n/v. Vitals stable. Labs normal. Except BUN 34 and creatinine 1.6 . Colonoscopy 6 months ago was unremarkable but somewhat limited in ascending colon d/t suboptimal bowel prep. What is most likely cause of symptoms

Angiodysplasia - episodic painless GIB. Angiodysplasia is dilated submucosal veins and AV malformations - has increased incidence after age 60. Can occur anywhere in GIT but right colon most common. More frequently diagnosed in patients with advanced renal disease, vWD - possibly d/t tendency to bleed with these disorders. Also more common in patients with aortic stenosis - possibly d/t acquired vW factor deficiency ( disruption of vW multimers are they traverse turbulent valve space induced by AS) - angiodysplastic bleeding has been seen to remit after AV replacement. DX: endoscopy eval (upper GI endoscopy, colonoscopy) - can easily be missed on colonoscopy d/t poor bowel prep or if located behind haustral fold. If ASX no treatment needed Patients with anemia or gross or occult bleeding can be treated endoscopically with cautery.

67 y/o male - n/v/ increasing abdominal pain x 3 hours. 1 month ago had MI. Has fever, pulse 110 and irregular. In severe distress d/t pain , bowel sounds decreased. Diffuse abdominal tenderness but more pronounced over RLQ - no peripheral edema. LAbs: low bicarb, elevated amylase. What is diagnosis

Bowel ischemia - Abrupt arterial occlusion d/t cardiac embolic event - afib , valvular disease or cardiovascular aneurysm - this patient likely developed left ventricular thrombus after MI - thrombus then embolized to mesenteric artery. - metabolic acidosis is suggested by the low bicarb. Dx: CT angio TX: open embolectomy with vascular bypass or endovascular thombolysis. Also start on broad spectrum abx and in absence of active bleeding - anticoagulation to reduce risk of clot expansion.

What labs are ordered for post surveillance of colorectal cancer

CEA - get pre op level to determine whether it would be a good tool LFT - unusual to have elevated LFT without corresponding CEA elevation If elevation in CEA get CT scan

Patient in snowmobile accident, FAST exam negative but presents with CVA tenderness and hematuria (ua shows 50-100 erythrocytes/hpf). What is most appropriate next step

CT scan of abdomen and pelvis - blunt genitourinary trauma with CVA pain and hematuria. All patients with BGT should undergo Ua and hemodynamically stable patients with evidence of hematuria should undergo further imaging with Contrast enhanced CT scan of abdomen and pelvis to identify and stage renal trauma. IF hemodynamically unstable with evidence of renal trauma - undergo IV pyelogram before surgical eval.

Patient who presents with fatigue, minor GI sx, iron deficiency anemia , dermatitis herptetiformis and elevated transaminases

Celiac sprue - screening: - antiendomysial or antitransglutaminase antibodies - many patients with biopsy confirmed celiac disease will have negative IgA ab testing - d/t associations with IgA deficiency - if high suspicion get total IgA or IgG based serology. Confirm dx: - small bowel biopsy - flattening of villi (villous atrophy) , also essential to r/o lymphoma Tx: gluten free diet NOTE: these patients have liftetime increased risk for osteoporosis and GI malignancies (enteropathy-assoc T cell lymphoma) - may suspect if refractory disease despite good diet control.

Patient with history of gallstones, presents with fever, jaundice and RUQ pain. Labs show increased ALP, increased total bili and CB, very high WBC. Abdominal u//s shows: dilated intrahepatic ducts and CBD without stones , and no gas in biliary tree or GB wall. What is diagnosis

Cholangitis - choledocholithiasis is mcc - TX: resuscitate - IVF and abx. - need urgent clearance of infection. ERCP if hemodynamically stable, PTC (percutaneous transhepatic cholangiography) if not stable. REmove GB before discharge NOTE: Most deadly feared complication is hepatic abscess.

What is purpose of D-xylose absorption test

D-xylose is absorbed in small intestine and doesnt need to be digested to be absorbed (absorbed in proximal small intestine without degradation by pancreatic or brush border enzymes - excreted in urine) - give to patient with chronic pancreatitis: should see d-xylose in urine - not malabsorption its digestion issue. - give to patient with celiac sprue - WONT SEE DXYLOSE IN URINE. Its not absorbed - low urinary and venous dxylose.

Sick patient with multi organ failure/sepsis. / in ICU - no history of GB disease but develop leukocytosis and fever, abdominal u/s shows dilated gall bladder , distention and pericholecystic fluid. What is management

DX: Acalculus cholecystitis - occurs in sick patients d/t cholestasis and GB ischemia secondary to infection from bile stains- edema and necrosis of GB TX: abx, percutaneous cholecystostomy (drain GB), then interval cholecystectomy 6-8 weeks later.

52 y/o - hx alcoholic liver disease - has fatigue and abdominal distension. No nausea/vomiting/constipation or diarrhea. Has chronic ascites treated with spironolactone and furosemide. Had inguinal hernia repair 20 years ago. Febrile, bp 102/68, pulse 106. Patient is awake and alert, oriented but fails to perform a timed connect the numbers test. Has ascites with diffuse discomfort to palpation. Bowel sounds decreased . Rectal exam normal. AXR shows dilated loops of large bowel with air in the colon and rectum . What is most likely diagnosis.

DX: SBP - SBP - ascitic fluid infection without an obvious intraabdominal surgical history (NOTE: adhesions cannot cause large bowel obstruction) Clinical presentation: - temp > 37.8 - abdominal pain/tenderness - AMS (abnormal connect the numbers test) - hypotension, hypothermia - PARALYTIC ILEUS WITH SEVERE INFECTION ******* (dilated loops of large bowel) DX from ascitic fluid - PMN > 250, positive culture (gram neg - e. Coli, klebsiella) - protein < 1 - SAAG > 1.1 TX: 3rd gen ceph (cefotaxime) fluoroquinolones are for SBP prophylaxis (cipro)

2 day old Asian girl - BGS negative, breastfeeding with good latch, voiding appropriately and passing meconium. Jaundice of face and neck present. Total bili 7, CB 0.4 what is most likely cause

Decreased hepatic uridine diphosphoglucuronate glucuronosyltransferase activity - common for jaundice between days 2-4 of life. HAve elevated hematocrit with high RBC turnover and bilirubin clearance slow because UGT acitvity takes 2 weeks to reach adult ability. ASians have high incidence.

What causes a false positive d-xylose test

Decreased urinary excretion despite normal absorption. PAtients with delayed gastric emptying or impaired GFR. Or small intestinal bacterial overgrowth - bacteria can ferment the d-xylose before it is absorbed - tx: rifaximin

Post gastrectomy patient - has had abdominal cramps and diarrhea - sx begin 25-30 minute after eating and are associated with nausea, weakness, palpitations, light headedness and diaphoresis. Has no symptoms overnight, no fever or weight loss. Vitals stable, CBC normal. What is most appropriate next step in management

Dietary modification. - DX: Dumping syndrome - common postgastrectomy complication in up to 50%. Caused by loss of normal action of pyloric sphincter d/t injury or surgical bypass and leads to rapid empyting of hypertonic gastric contents into duodenum and small intestine. Causes fluid shifts form intravascular space to the small intestine, leading to hypotension, stimulation of autonomic reflexes, release of VIP. DX: clinical - can use upper GI xray series or gastric emptying study if needed TX: Dietary modification - consume frequent, small meals and eat slow. - avoid simple sugars - increase fiber and protein - drink fluids between rather than during meals Sx usually diminish over time. If refractory sx - can try octreotide or reconstructive surgery

What is most common cause of colovesical fistula

Diverticulitis - fistula between colon and bladder. Sx: pneumaturia , recurrent UTI in menand caused by variousorganisms. Dx: CT scan - shows inflammatory mass from diverticulitis - may do sigmoidoscopy to rule out cancer (can present with fistulas) tx: Surgery

70 y/o - had bowel movement with large volume of bright red blood without pain. Has lightheadedness along with several urges to defecate where blood is produced. No PMH GI bleeding. PMH HTN and chronic constipation. VS 85/45, pulse 120 . Abdomen soft, nondistended and nontender. Bowel sounds normal. Rectal exam shows bright red blood. NGT is nonbilious without blood. AXR normal. What is most likely cause of bleeding

Diverticulosis - mcc of LGIB in adults. (Large volume arterial hemorrhage vs. angiodysplasia - low vol venous bleeding) - diverticular are outpouchings of colonic wall that forms at weak points -deformation in colonic wall can cause weakness in the associated arterial supply and lead to bleeding in diverticular lumen. Most common in sigmoid but diverticular bleeding is most common in right colon. Bleeding is usually painless - if large volume bleed can present with lightheadedness and hemodynamic instability. Dx: Colonoscopy - most cases resolve spontaneously.y

45 y/o male - persistent vomiting of partially undirected food x 1 month. Appetite is good but has early satiety. Had suicide attempt 3 months ago where he ingested acid. Has HX of PUD and heartburn. Drinks and smokes. Abdominal exam shows SUCCUSSION SPLASH ON EPIGASTRIUM. What is diagnosis

Dx: Pyloric stricture - signs and symptoms of gastric outlet obstruction d/t mechanical obstruction, leading to postprandial pain and vomiting with early satiety Common causes of gastric outlet obstruction: gastric malignancy, PUD, chrons, strictures (with pyloric stenosis) secondary to ingestion of caustic agents and gastric bezoar. Physical exam shows abdominal succussion splash - elicited by placing stethoscope over upper abdomen and rocking patient back and forth at hips. Retained gastric material for > 3 hours after a meal will generate a splash sound and indicate presence of a hollow viscous filled with both fluid and gas. Acid ingestion causes fibrosis within 6-12 weeks after resolution of acute injury - dx: upper endoscopy , treatment is surgical.

When do hernias go to OR (elective vs. soon vs. emergent)

Emergent = black/blue, acute abdomen, sepsis - strangulated with compromised blood supply - leading to necrosis and ischemia Soon = acutely irreducible or with SBO but no emergent signs (still have intact blood supply) - incarcerated Elective = reducible hernia, symptomatic and no SBO or acute abdomen

3 hour old newborn in nursery, choking, coughing and regurgitating after first milk feed. Born at 41 weeks vaginally. Second and third trimester u/s showed polyhydramnios. Clear amniotic fluid was seen after ROM. Tachycardic, tachypneic, hypoxic. Crackles are heard in the right lower lobe. Anus is patent. Endotracheal and orogastric tubes inserted. An umbilical venous catheter is placed. XRAY shows dilated loops of bowel and enteric tube in proximal esophagus. What is most likely diagnosis?

Esophageal atresia with TEF - the TEF permits air entry into GIT , the stomach and intestines become distended with each breath - esp in ventilated patient. Typically present exhibit vomiting with first feed or chocking/coughing and cyanosis - gastric fluid can reflux into distal esophagus through the fistula and into trachea and lungs, causing aspiration pneumonia - this patients crackles on exam, may have infiltrates in lung - consistent with pneumonia ASSOC: VACTERL - vertebral - anal atresia - cardiac - TEF - REnal - Limb

Patient with chronic GERD, now has new onset dysphagia to solids only, EGD shows symmetric circumferential narrowing at distal esophagus

Esophageal stricture - chronic GERD predisposes to Barrett's and strictures. Consequences of repetitive acid exposure. Other causes of strictures: radiation, systemic sclerosis, caustic ingestions.

In blunt abdominal trauma, after ABC and fluid resuscitation what is the next best step in an alert and hemodynamically stable patient (SBP >90)

FAST - eval abdomen and pericardium for organ injury or hemorrhage - if positive - can do CT scan (if stable) to eval for need for laparotomy IF hemodynamically unstable patient has positive FAST - ex lap

What is complication of chronic perianal abscess

Fistula in ano (Anal fistula almost always precedes history with anal abscess) - if abscess cavity doesnt heal - leads to partial tract epithelialization , cavity becomes an inflammatory tract with a primary (internal) opening in the anal crypt at dentate line, and secondary (external) opening in perianal skin. - will have sentinel pile with purulen or serosanguinous drainage on palpation/compression. Tx: unroof fistula- eliminate primary opening, establish drainage.

82 y/o female - severe abdominal pain and vomiting. Nausea and anorexia x 5 days. Has had several mild, self resolving episodes of vomiting, abdominal pain and bloating. PMH: DM, htn, mvp, gallstones and constipation. Abdomen soft but distended with hyperactive bowel sounds. Elevated WBC and mild elevation of liver transaminases. AXR shows dilated loops of small bowel and air in the intrahepatic bile duct. What is most likely cause of symptoms

Gallstone Ileus. - Mechanical bowel obstruction. DX: gallstone ileus. - n/v/ pneumobilia (air inbiliary tree) , hyperactive bowel sounds and dilated loops of bowel . - when gallstone passes through a biliary-enteric fistula into small bowel =- may cause intermittent "tumbling" obstruction n with diffuse abdominal pain until lodging into ileum - narrowest section. Dx: abdominal CT scan - GB wall thickening, pneumobilia , obstructing stone TX: relieve acute SBO - proximal enterotomy with stone removal. Repair biliary fistula and remove GB after recovery of SBO.

FAP with osteomas, cutaneous Desmond's and fibromas

Gardner's syndrome

4 wk old, had small spit ups after feeding , now had forceful emesis after every feed - nonbilious or bloody. Weight is unchanged from birth. Awake and alert, despite throwing up still hungry. Anterior fontanel is sunken, decreased skin turgor, abdomen soft, nontender and nondistended without masses. What is most likely cause of vomiting

Gastric outlet obstruction. - DX: pyloric stenosis "Hungry vomitor" postprandial projectile vomiting followed by hunger - irritable and hungry - gastric obstruction, no formula gets into intestine for absorption - remain hungry after every episode of vomiting. Formula feeding can cause gradual hypertrophy of pylorus, slower gastric emptying and consume more volume in lest time - pyloric muscle hypertrophies with time. Can have palpable mass in epigastrium "palpable olive like mass"

Defect to the right of the cord insertion not covered by membrane or skin, contains bowel, umbilical cord inserts next to defect

Gastroschisis - maternal AFP usually elevated, can detect defect on u/s during second trimester. - not covered in sac - bowel is exposed to amniotic fluid - causes inflammation and edema of bowel wall. Inflammation increases risk of complications (necrotizing entercolitis, short bowel syndrome) - dysmotility (ileus, delayed gastric emptying, intolerance of feeds) occcur in over 50% and can lead to prolonged reliance on TPN - isolated defect > 90% of time

Diarrhea acquired during international travel that includes abdominal cramps, foul-smelling stools, bloating and benign findings on abdominal exam and no response to ciprofloxacin

Giardiasis. (Giardia duodenalis - sometimes G lamblia or G intestinalis) - common in rural areas (south america) or developing cuntries - incubation period of 1-2 weeks - most commonly transmitted by contaminated water. Can be food born or person to person. - most asx, some can develop chronic giardiasis with malabsorption, weight loss, persistent GI distress. Dx: Stool antigen assay (direct immunofluorescence or ELISA) - or stool microscopy for oocysts and trophozoites. TX: Metronidazole (asx carriers dont need treatment)

16 y/o - had appendectomy 3 days ago. Now has yellowing of eyes, has no abdominal pain or nausea and is tolerating normal diet. Vitals stable. Mild scleral icterus. Abdominal surgical incisions healing well without redness. Total bilirubin is 3.3, direct is 0.4 What is most likely diagnosis?

Gilbert Syndrome - inherited disorder of bilirubin glucuronidation - AR or AD mutation in UGT1A1 gene - decreased UDP glucuronosyltransferase activity - increased UCB. - can present with intermittent episdoes of jaundice precipitated by stress (infection, fasting, exercise, surgery) All labs will be normal except mild increase in indirect bilirubin. Tx: none Dx: elevated levels of UCB on repeat testing with normal LFT and CBC results

When do you screen for colon cancer in patient w/ HNPCC, FAP, UC, first degree relative with hx, personal hx of colon cancer

HNPCC - start at age 21 q 1-2 years and every year after 40 FAP - start at puberty (12) and then annually UC - start after 8 years from diagnosis then annual First degree relative - start at age 40 or 10 years from diagnosis whichever comes first. Personal hx - 1 year after cancer detected, if normal - follow up within 3 years, if normal every 5 years.

In blunt abdominal trauma - fracture of right 8th and 9th ribs can cause what complication

Hepatic laceration - one of most common solid organ injuries Other manfiestations (hypotensive, tachycardic) also RUQ and right shoulder pain from irritation of phrenic nerve

What electrolyte disturbance is present with pyloric stenosis

Hypochloremic hypokalemic metabolic alkalosis - with paradoxical aciduria - vomiting - loss of HCl , potassium and fluid. Loss of ECF - activates RAAS - increase aldosterone (increase potassium and hydrogen excretion)

Pain syndrome that presents with constipation/diarrhea or both . Pain is relieved by a BM, no nocturnal sx, relieved by change in bowel habits.

IBS. Rome II criteria: clinical dx - recurrent abdominal pain/discomfort > 3 days/mo in last 3 months - 2 or more of: sx improve with defecation/ change in stool freq or appearance. No sx at night. Tx: fiber, antispasmodic (hyosyamine, dicyclomine) , TCA, antimotility (loperamide) lubiprostone (constipation dominant)

58 y/o male - skin discoloration, anorexia and weight loss x3 months. BMI 32. Scleral icterus. Enlarged nontender gallbladder. No ascites. What would abdominal imaging most likely show

Intra- and extra hepatic biliary tract dilation. Dx: Pancreatic cancer. - pain less jaundice , distended painless gallbladder (Courvoisier sign) - jaundice can lead to pruritus, pale stools and dark urine.

Adult onset diarrhea - no weight loss associated - watery diarrhea after meals, gas and bloating, no blood or WBC in stool

Lactose intolerance. - dX: Stool osmolality increased , lactose is extra osmole (decreased stool pH) acidic pH from fermentation of products Hydrogen breath test - give oral lactose to patient in fasting state, measure breath hydrogen levels at baseline, 30 min increments for 3 hours - positive test if > 20 ppm increase in breath hydrogen level Usually way to diagnose is to remove all dairy products and see resolution of symptoms. Tx: oral lactase replacement, also make sure to maintain calcium and vitamin d supplementation - restricting dairy Can result in inadequate ingestion - increase risk of osteoporosis and fractures.

UGIB after prolonged vomiting or retching - seen in alcoholic or bulemic. D/t mucosal tear at GE junction (submucosal arterial or venous plexus bleeding ) from sudden increase in intrabdominal pressure

Mallory- Weiss tear. Dx: EGD TX: 90% resolve spontaneously, if active bleeding on EGD can do sclerotherapy (inject epi), cauterization, embolization. Give PPI to decrease acidity.

What is a complication of untreated fistula

Marjolin ulcer - squamous cell carcinoma can arise from constantly irritated draining fistula

63 y/o male - several weeks of vague abdominal pain and tired. Smokes a pack a day and drinks beer on weekends. Has mildly distended, soft abdomen, liver edge is hard and palpated 5 cm below the costal margin. No hepatojugular reflex. Trace ankle edema. Labs show microcytic anemia and elevated ALP. CXR shows small left sided pleural effusion, FOBT is positive. What is most likely cause of hepatomegaly?

Metastatic disease - has typical features of GI malignancy - likely colon cancer with mets to liver. (Liver is most common site) - has small pleural effusion that may be malignant - (note hepatic hydrothorax more likely occurs on right) Patient needs CT scan with IV contrast to eval for malignancy.

65 y/o male - difficulty swallowing and coughing during meals. Right-sided neck mass that increases in size while drinking fluids. Has bad breath and occasionally regurgitates medications taken early in day. PMH: htn, gerd , OA. What is most important pathogenic factor in development of patients problem>?

Motor dysfunction - dx: zenker diverticulum. Dysphagia, coughing, regurgitation, halitosis and neck mass - in someone > 60. Depending on food and fluid intake, neck mass can vary in size and cause gurgling in throat. Develops immediately above the upper esophageal sphincter with posterior herniation between the fibers of the cricopharyngeal muscle - upper esophageal sphincter dysfunction and esophageal dysmotility are believed to cause ZD. Dx: Barium swallow (esophagram) / "contrast esophagram" Tx: excision , cricopharyngeal myotomy

What is non operative management for SBO

NPO, NGT ambulation 75% will resolve within 48-72 hours with bowel rest and decompression - if symptoms persist or clinically deteriorate (pain turns constant and more localized) may need surgery

2 y/o brought to physician because of bluish skin nodules, periorbital proptosis, and periorbital ecchymosis - on physical exam there is a smooth abdominal mass that is palpated.

Neuroblastoma - tumor from neural crest cells, d/t n-myconcogene. (Poor prognosis with amplification of n-myc) - precursors to cells of sympathetic chain and adrenal medulla. Present with abdominal distension, irregular mass that CROSSES MIDLINE. , CAN BE PAINFUL, and may see calcification and hemorrhage on xray or CT . Can also present with systemic sx (fever, fatigue, malaise) Initial presentation often has mets - long bones, skull, orbital , BM, liver, skin. Most are in the adrenal gland but can arise from retroperitoneal sympathetic ganglia (or cervical, thoracic or pelvic ganglia) Assoc paraneoplastic syndromes: - opsoclonus, myoclonus - myoclonic jerks of extremities - chaotic eye movements. Histo - small round blue cells with dense nuclei - homowrisght rosettes DX: break down products of dopamine - HVA and VMA - xray, ct scan and MRI Bombesin and neuron specific enolase positive. Can do body scan with 1 - MIBG (label with octreotide) Tx: Surgery, chemo and radiation, stem cell transplant is definitive.

Colon cancer to liver mets - what is criteria for surgical excision (LOOK UP REST)

No extra-hepatic disease, surgically resectable, operative candidate

Midline abdominal wall defect covered by peritoneum, contains multiple abdominal organs, umbilical cord inserts at apex of defect.

Omphalocele - other malformations. - cardiac disease, NTD or trisomy syndromes occur in approximately half of patients. Tx: staged closure with silastic silo

What associations are common with celiac sprue

Other autoimmune diseases - type I DM, hypothyroidism, vitiligo Iron deficiency anemia (unexplained) Vitamin D or K deficiency - bone pain / fractures (osteomalacia or osteoporosis) Vitamin A deficiency - hyperkeratosis

Abscess of an infected follicle found on the small of the back - painful fluctuant mass 4-5 cm cephaled to anus (midline sacrococcygeal) with mucoid, purulent bloody drainage

Pilonidal disease Seen in young males, obese with sedentary occupation or if deep gluteal cleft. Pain is worsened by activities that stretch overlying skin (bending down) Develops when infected hair follicle in intergluteal region becomes occluded. Subcutaneous infection spread - forms abscess that can rupture and create pilonidal sinus tract. As patient sits/stands, hair and debris are forced into sinus tract - recurrent infections and foreign body reactions. Tx: Drain abscess / debris and excise sinus tract - open closure.

45 y/o Asian female - bloating, flatulence, abdominal cramps and explosive watery diarrhea - occur after ingesting dairy. No weight loss. No bone pain or easy bruising. Physical exam shows abdominal distension and borborygmi . What test result is likely to be observed

Positive hydrogen breath test DX: Lactose intolerance. - lactase is brush border enzyme that hydrolyzes lactose. When theres inability to absorb lactose = lactose intolerance. Asian americans most commonly have this. Manifest with osmotic diarrhea, abdominal cramps and bloating and flatulence after ingestion of dairy. DX: lactose hydrogen breath test - rise in measured breath hydrogen level after ingestion of lactose (indicates bacterial carb metabolism) The diarrhea secondary to lactase deficiency has HIGH OSMOLAR GAP - d/t unmetabolized lactose and organic acids , stool pH is acidic. - d/t fermentation of products.

23 y/o - 20 week obstetric u/s. - increased serum AFP in first trimester. U/s shows fetus with thickened intestinal loops that are floating free in the amniotic sac. What outcome is most likely assoc with fetus condition

Primary surgical closure after birth Dx. Gastroschisis

2 month old full term girl - drinks 5 oz of standard cow's milk q 4 hours. She regurgitates a small amount of formula after each feed - gets fussy when it comes out of her nose but calms down after burping. Has no coughing, gagging or breathing difficulties. Growth along 25th percentile. Smiling and cooing. Lungs clear, abdomen nondistended and nontender. What is next best step

Provide reassurance This is GERD - physiologic - baby is asymptomatic - management is reassurance and positioning therapy. - GERD is very common and affects up to 50% of infants. Infants experience frequent postprandial regurg "spitting up" d/t shorter esophagus, incomplete closer of LES and greater time spent in supine position. Tx: education and support. - advise parents to give frequent, small volume feeds, hold infant upright for 20-30 minutes after feeds, place infant prone when awake. - activities that increase intraabdominal pressure (fastening diaper too tight) should be avoided Regurgitation usually improves around age 6 months, once infant can sit unsupported and resolves by 1 year

What is pathophys behind dehydration in SBO

Proximal obstruction - repeated emesis, anorexia Compete obstruction - transudative loss of fluid into peritoneal cavity Intestine proximal to obstruction - becomes distended from gas and GI secretions accumulating - have stasis in intestinal lumen - bacteria overgrow and ferment = increase dilation. AS hydrostatic pressure in the intestinal lumen increases - fluid accumulates in bowel wall, alters starling forces and have net filtration of fluid, electrolytes and protein into bowel wall and lumen. = THIRD SPACING. - loss of fluid from intravascular space - further contributes to dehydration May see prerenal azotemia, hypochloremic hypokalemic metabolic acidosis.

Milk protein allergy

RF: allergies, asthma, eczema Presents at 2-8 weeks, regurgitation or vomiting, with our without painless bloody stools, with or without eczema. - exclusive to infants, non IgE mediated immunologic process in response to proteins in formula or breast milk that cause rectal or colonic inflammation Dx: clinical, confirm when bleeding ceases in response to dietary changes. TX: need to avoid dairy and soy - if breast fed - mom can continue once eliminating all dairy and soy from her diet. If formula fed - give hydrolyzed formula (contains predigested proteins) Usually resolves by 1 year of age

20 y/o college student ingests large amounts of acetaminophen in suicide attempt - took 30 pills of 500 mg. Reports nausea, mild abdominal pain - had mild hepatomegaly . Serum acetaminophen level is high, hospitalized for N-acetylcysteine therapy. Becomes confused and incoherent during hospital stay, has scleral icterus and asterixis. Current labs since admission show AST/ALT at 8,456 / 9,634 PT 120 sec and creatinine 3.5 mg/dL. What is next best step in management

Refer to liver transplant center. Patient has developed acute liver failure d/t acetaminophen toxicity. ALF is acute liver injury without underlying liver disease - elevated aminotransferases (> 1,000) , hepatic encephalopathy and synthetic liver dysfunction (prolonged PT with INR > 1.5) Reliable indicators of worsening ALF - rising bilirubin and PT. Acute renal insufficiency , likely d/t decreased renal perfusion Cerebral edema is a common complication of ALF - can lead to coma and brain stem herniation - MCCOD.

Ischemic Colitis d/t state of low blood flow (hypovolemia) or non occlusive - where are the most commonly involved segments of the colon

Splenic flexure- between SMA and IMA And rectosigmoid junction (sigmoid artery and superior rectal artery) CF: moderate abdominal pain and tenderness, hematochezia, diarrhea, leukocytosis and lactic acidosis. DX: CT scan - colonic wall thickening, fat stranding. If immediate surgical intervention needed (extensive damage or perforation) - colon resection If colon resection not needed - give IVF abx and do colonoscopy to confirm : - will find pale mucosa with petechial bleeding, bluish hemorrhage nodules or cyanotic mucosa with hemorrhage.

What is management for acute exacerbations of IBD

Steroids with flares . Always r/o infection - esp c diff. Abx - metronidazole and cipro If perianal disease- drain If right sided disease - budesonide.

52 hour old girl develops vomiting and abdominal distention. Delivered at 40 weeks by c/s d/t failure to progress. Has voided but hasnt passed meconium. Has spit up all feeds and now has bilious emesis. Abdomen is tense and distended. REctal exam shows no stool in the rectal vault and normal tone. Feeds held, NGT placed for decompression. Upright abdominal radiograph shows multiple dilated loops of small bowel with paucity of air in the large intestine and rectum. Left lateral decubitus shows free air above the liver - emergent ex lap performed. Viscous meconium is irrigated and evacuated, primarily from the ileum and some from the colon. Colon found to be diffusely narrow - what underlying condition while this patient most likely deveop

Chronic rhinosinusitis Dx:MEconium ileus - earliest manifestation of CF, basically diagnostic. Mutation in CF transmembrane conductance regulator gene - abnormal chloride and sodium transport and thick viscous secretion in multiple organs - thick inspissated meconium - difficult to propel , resulting in obstruction at level of ileum and narrow, underdeveloped colon In this case - free air above liver suggests intestinal perforation and warrants urgent ex lap Nearly all patients develop recurrent sinopulmonary disease - opacification of all sinuses can be seen as early as 8 months - some require surgical debridement of sinuses.

Patient with chronic abdominal pain, weight loss, granulomatous oral ulcers (aphthous ulcers) and anal fissures/skin tags

Chrons disease. F> M Smoking is RF. Transmural inflammation - granulomas on biopsy Assoc: anti-saccharomyces cerevisiae antibodies (ASCA) - NOD2 gene - involves terminal ileum - B12, ADEK deficiency. IF duodenum involved - Iron deficiency. Osteopenia

What can be given as empiric treatment for travelers diarrhea (loose or watery stools - reserve for moderate to severe cases)

Ciprofloxacin (quinolones) If child or pregnant - Azithromycin Common etiologies: ETEC, campylobacter, salmonella

Crying that occurs in an otherwise healthy infant for > 3 hours daily (usually evening) , > 3 times a week and for a duration of > 3 weeks. USually presents in first few weeks of life and resolves spontaneously by 4 months. Crying generally occurs at the same time of day, usually in the evening

Colic - TX: inform parents that its common, and reassure them that baby is healthy. Calming techniques - infant swing - swaddling - minimize environmental stimuli (dark quiet room) - holding and rocking baby - assess feeding patterns -over feeding, underfeeding or inadequate burping

What trace mineral is deficient in patient on TPN who presents with fragile/brittle hair, skin depigmentation, neurologic dysfunction (ataxia, peripheral neuropathy), sideroblastic anemia, osteoporosis

Copper - can mimic B12 deficiency

1 y/o poor weight gain. Since birth has had greasy and loose stools. Recently started drinking cow's milk; drinks about 20 oz of whole milk and eats table food - meats, fruits and grains 3-4 times a day. Has also had recurrent nosebleeds over the past month. Had 3 prior hospitalizations for bronchiolitis, mom says hes had a cough that has persisted for a month after last discharge. HE and mom live with boyfriend who smokes cigs. Physical exam shows thin kid with dried blood on nasal turbinates, bilateral wheezes on auscultation, scattered ecchymoses on extremities, what is most likely cause of kids failure to thrive.

PANCREATIC INSUFFICIENCY. - kid has CF - if not identified by newborn screening or meconium ileus at birth, growth failure and recurrent sinopulmonary infections occur. - most common GI manifestation of CF is pancreatic insufficiency - pancreatic duct obstruction and distension d/t viscous mucus and subsequent inflammation develop in utero - eventually leading to fibrosis. - pancreatic insufficiency is present from birth in most patients with CF and results in inability to absorb fat and fat soluble vitamins (ADEK) - steatorrhea , failure to thrive and vitamin deficiencies - vitamin K - prolonged PT with easy mucosal bleeding (epistaxis ) and bruising NOTE: growth chart in infants with CF - normal birth measurements with deceleration in weight ( > 2 major percentiles) followed by deceleration in length - in addition to malabsorption - recurrent sinopulmonary infections impair growth d/t poor appetite and increased metabolic needs during illness.

Diarrhea, dermatitis, dementia

PEllagra - d/t niacin deficiency - dermatitis - sun exposed areas, rough hyperpigmented scan skin (malar distribution on face, neck and back of hands) - dementia - neuronal degeneration in brain and spinal cord - memory loss, depression and psychosis. Can be d/t poor intake (alcoholic, chronic illness) - carcinoid - tryptophan depleted to make 5HT - hartnup disease - congenital disorder of tryptophan absorption Prolonged in - can sometimes interfere with tryptophan metabolism.

What is treatment for h. Pylori

PPI, clarithromycin and amoxicillin x 2 weeks - breath or stool test for cure (cant use serum )

46 y/o - in bike accident - CT of abdomen reveals small retroperitoneal bleed and splenic lac. Lumbar film reveals a compression wedge fracture in L2 and a brace is placed. Conservative management with analgesics and supportive measures. On hospital day 3 - mild diffuse abdominal pain and nausea- abdomen is distended, tympanic and mildly tender without rebound or guarding. Bowel sounds absent. Xray shows dilated loops of bowel - what is most likely diagnosis

Paralytic (adynamic ) ileus. - abdominal xray with gas filled loops of bowel in both small and large intestines as well as gastric dilation. Ileus is most commonly d/t abdominal surgery but can also be seen with retroperitoneal/abdominal hemorrhage, inflammation, intestinal ischemia and electrolyte abnormalities (hypokalemia) - increased splanchnic nerve sympathetic tone following irritation of peritoneum, local release of inflammatory mediators and opioids also contribute Signs and sx: n/v/ abdominal distension, failure to pass flatus or stool (obstipation) hypoactive/absent bowel sounds Clinical diagnosis and AXR shows dilated gas filled loops of bowel with no transition point Management - bowel rest, supportive care and treat secondary causes.

What is dangerous complication of PUD

Perforation - free air under diaphragm (between diaphragm and liver) - with severe epigastric pain. Management is urgent ex lap

44 y/o man- severe perianal pain, cant sit down has chills with fever, hard tender fluctuant mass between anus and ischial tuberosity

Perianal abscess - I&D in OR - occurs in crips of glands at dentate line - ducts of glands get blocked, pus forms in glands and forms an abscess around skin of anus

MCC diarrhea in kids < 2 , fecal oral route. PEaks in winter - water, non bloody diarrhea that lasts < 7 days

Rotavirus. - recent hx of URI (viral prodrome) - now have oral vaccine

What is the most accurate diagnostic test for chronic pancreatitis

Secretin stimulation test - place NGT - an unaffected pancreas will release a large volume of bicarb rich fluid after IV infection of secretin.

What trace mineral is deficient in patient on TPN who presents with thyroid dysfunction, cardiomyopathy (JVD , lower extremity edema) and immune dysfunction

Selenium

53 y/o woman - right sided abdominal pain x 2 days. Constant, burning and interferes with sleep. No nausea/vomiting or diarrhea. OTC antacids and ibuprofen dont relieve. PMH breast cancer - had radical mastectomy followed by chemo - last course 3 weeks ago. Vitals stable, abdomen soft, nondistended, no rebound,guarding or rigidity. Lightly brushing the skin to the right of the umbilicus elicits intense pain - what additional feature is most likely to develop

Skin lesions - burning localized pain, regional hyperesthesia/ allodynia in context of recent cancer treatment - feat of herpes zoster (shingles) - pain from shingles may preced the onset of classic vesicular rash by several days - consider possibility of shingles in patients with regional pain who have no conclusive evidence of disease in local internal organs. Most common after age 50 - triggered by physical stress (Cancer treatment) or immunosuppression. Develop with reactivation of varicella zoster in DRG - results in apainful vesicular rash along dermatomal distribution along course of nerve. Some can develop persistent hypersensitivity of afferent pain fibers leading to chronic pain - post-herpetic neuralgia. Tx: antivirals (acyclovir, valacyclovir, famciclovir) in first few days of outbreak - shorten duration and decrease risk of post herpetic neuralgia.