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COMLEX Level 2-CE - independent subject foundations study materials
COMLEX Level 2-CE - independent subject foundations study resources

COMLEX Level 2-CE - independent subject foundations practice questions

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Question 1Internal medicine: physiology, differential diagnosis and clinical priorities

A 58-year-old man with diabetes and hypertension presents to the emergency department with crushing substernal chest pain for 45 minutes. ECG shows 3-mm ST elevation in leads II, III, and aVF with reciprocal depression in I and aVL. Which artery is most likely occluded?

  1. Left anterior descending (LAD)
  2. Right coronary artery (RCA) Correct answer.
  3. Left circumflex artery (LCx)
  4. Left main coronary artery

Explanation

ST elevation in the inferior leads (II, III, aVF) localizes the infarct to the inferior wall, which is most commonly supplied by the right coronary artery (RCA) in approximately 80-90% of patients (right-dominant circulation). Reciprocal depressions in the high lateral leads (I, aVL) further support an inferior STEMI from RCA occlusion.

Question 2Internal medicine: physiology, differential diagnosis and clinical priorities

A 55-year-old woman is found to have a TSH of 0.02 mIU/L with free T4 of 3.2 ng/dL. She reports palpitations, heat intolerance, and unintentional weight loss. Examination shows exophthalmos. What is the most likely diagnosis?

  1. Hashimoto thyroiditis
  2. Graves disease Correct answer.
  3. Subacute (de Quervain) thyroiditis
  4. Toxic multinodular goiter

Explanation

Hyperthyroidism with exophthalmos (and likely pretibial myxedema and thyroid bruit on exam) is pathognomonic for Graves disease, an autoimmune disorder mediated by TSH receptor antibodies (TRAb). Confirmation is via elevated TRAb or diffusely increased uptake on RAIU scan. Treatment options include methimazole, radioactive iodine, or thyroidectomy.

Question 3Internal medicine: physiology, differential diagnosis and clinical priorities

A 30-year-old woman presents with a 6-month history of intermittent diarrhea, abdominal pain, and 10-lb weight loss. Colonoscopy shows skip lesions in the terminal ileum with cobblestoning. What is the most likely diagnosis?

  1. Ulcerative colitis
  2. Crohn disease Correct answer.
  3. Celiac disease
  4. Irritable bowel syndrome

Explanation

Crohn disease classically presents with skip lesions, terminal ileum involvement, transmural inflammation, cobblestoning, and granulomas on biopsy. It is distinguished from ulcerative colitis by patchy distribution (vs continuous), small bowel involvement (vs colon only), and transmural inflammation (vs mucosal only). Management includes induction with corticosteroids then maintenance with immunomodulators or biologics (anti-TNF, anti-integrin, anti-IL-12/23).

Question 4Internal medicine: physiology, differential diagnosis and clinical priorities

A 45-year-old man with type 2 diabetes presents for follow-up. His HbA1c is 8.2% despite metformin 1000 mg twice daily. He has CKD (eGFR 50) and is overweight (BMI 32). Per ADA 2026 guidelines, what is the best next addition?

  1. Insulin glargine
  2. Glipizide
  3. An SGLT2 inhibitor (e.g., empagliflozin) Correct answer.
  4. Pioglitazone

Explanation

ADA 2026 recommends SGLT2 inhibitors or GLP-1 receptor agonists as add-on to metformin in patients with established or high risk of ASCVD, heart failure, or CKD, independent of HbA1c. SGLT2i (empagliflozin, dapagliflozin) reduce cardiovascular and renal events and are first-line second agent for CKD plus diabetes. GLP-1 RAs (semaglutide, liraglutide) are alternatives, especially when weight loss is a priority.

Question 5Internal medicine: physiology, differential diagnosis and clinical priorities

A 50-year-old woman with a history of breast cancer treated with chemotherapy presents with progressive dyspnea and orthopnea. Echo shows EF 35% with global hypokinesis. Which chemotherapy is most likely responsible?

  1. Doxorubicin (anthracycline) Correct answer.
  2. Vincristine
  3. Tamoxifen
  4. Letrozole

Explanation

Anthracyclines (doxorubicin, daunorubicin, epirubicin) cause dose-dependent cardiomyopathy via free radical injury to cardiomyocytes. Cumulative dose >=400-550 mg/m2 significantly increases risk of HF. Trastuzumab also causes cardiomyopathy but is typically reversible. Cardio-oncology surveillance with periodic echo or cardiac biomarkers (troponin, BNP) is recommended.

Question 6Internal medicine: physiology, differential diagnosis and clinical priorities

A 60-year-old man with diabetes presents with foot pain and erythema for 2 days. Exam shows a deep ulcer on the plantar surface with surrounding cellulitis. X-ray shows cortical destruction of the underlying metatarsal. What is the most likely diagnosis?

  1. Cellulitis only
  2. Osteomyelitis with soft tissue infection Correct answer.
  3. Charcot arthropathy
  4. Gout

Explanation

Diabetic foot ulcer with surrounding cellulitis and X-ray evidence of cortical destruction is diagnostic of osteomyelitis with soft tissue infection. Probe-to-bone test, elevated ESR/CRP, and MRI confirm the diagnosis. Management requires broad-spectrum antibiotics (e.g., piperacillin-tazobactam or vancomycin plus piperacillin-tazobactam), bone biopsy for culture-directed therapy, and surgical debridement.

Question 7Internal medicine: physiology, differential diagnosis and clinical priorities

A 38-year-old man presents with progressive jaundice, pruritus, and dark urine. AST 95, ALT 80, alk phos 580, total bilirubin 8.2 (direct 6.5). MRCP shows multifocal strictures and beading of intrahepatic bile ducts. Colonoscopy shows ulcerative colitis. What is the most likely diagnosis?

  1. Primary biliary cholangitis
  2. Primary sclerosing cholangitis Correct answer.
  3. Choledocholithiasis
  4. Pancreatic head cancer

Explanation

Primary sclerosing cholangitis (PSC) is characterized by intrahepatic and extrahepatic biliary strictures with beading on MRCP, strongly associated with inflammatory bowel disease (especially ulcerative colitis in 70-80% of PSC cases). It carries elevated risk of cholangiocarcinoma and colon cancer (annual colonoscopy). Liver transplantation is the only definitive treatment; ursodeoxycholic acid does not improve survival.

Question 8Internal medicine: physiology, differential diagnosis and clinical priorities

A 30-year-old woman presents with daily morning stiffness >1 hour, symmetric polyarthritis of the MCP and PIP joints, and positive RF and anti-CCP antibodies. What is the most appropriate first-line disease-modifying therapy?

  1. NSAIDs only
  2. Methotrexate Correct answer.
  3. Prednisone monotherapy
  4. Hydroxychloroquine alone

Explanation

Rheumatoid arthritis with positive serologies and symmetric polyarticular involvement requires prompt initiation of disease-modifying antirheumatic drug (DMARD) therapy to prevent joint erosion. Methotrexate is the first-line DMARD (10-25 mg weekly with folate supplementation), often with low-dose prednisone bridge until methotrexate takes effect (~6-8 weeks). Combination DMARD or biologic therapy is added if methotrexate alone is inadequate.

Question 9Internal medicine: physiology, differential diagnosis and clinical priorities

A 50-year-old chronic alcoholic with cirrhosis presents with confusion, asterixis, and elevated ammonia level (180 mcg/dL). His diet history shows recent constipation. What is the most appropriate first-line treatment?

  1. Lactulose titrated to 2-3 soft stools per day Correct answer.
  2. Neomycin alone
  3. High-protein diet
  4. Vasopressin infusion

Explanation

Hepatic encephalopathy is treated first with lactulose (a non-absorbable disaccharide that traps ammonia in the colon as NH4+) titrated to produce 2-3 soft stools daily. Rifaximin (550 mg twice daily) is added if recurrent or refractory. Identifying and treating precipitants - GI bleed, infection (SBP), constipation, electrolyte abnormalities, sedatives - is essential.

Question 10Internal medicine: physiology, differential diagnosis and clinical priorities

A 70-year-old presents with painful, vesicular rash in a dermatomal distribution on the right T6 dermatome for 2 days. He has not had chickenpox vaccination. Per current guidelines, what is the appropriate antiviral and timing?

  1. Acyclovir, only if started >72 hours after rash onset
  2. Valacyclovir 1 g PO three times daily for 7 days, started within 72 hours of rash Correct answer.
  3. IV ganciclovir
  4. Famciclovir only after rash resolves

Explanation

Herpes zoster (shingles) is treated with oral antivirals - valacyclovir 1 g PO three times daily for 7 days, famciclovir 500 mg three times daily, or acyclovir 800 mg five times daily for 7 days - ideally within 72 hours of rash onset to reduce duration of acute pain and incidence of postherpetic neuralgia (PHN). Postherpetic neuralgia treatment includes gabapentin, pregabalin, TCAs, and topical lidocaine.

Question 11Internal medicine: physiology, differential diagnosis and clinical priorities

A 45-year-old African American man with hypertension is poorly controlled on hydrochlorothiazide and amlodipine. Per JNC and ACC/AHA guidelines, what is the most appropriate next step?

  1. Add a beta-blocker
  2. Add an ACE inhibitor or ARB Correct answer.
  3. Increase HCTZ to 50 mg
  4. Refer for surgery

Explanation

For African American adults without comorbid CKD or HF, first-line antihypertensive therapy is a thiazide diuretic OR calcium channel blocker. When these are inadequate, adding an ACE inhibitor or ARB is reasonable as combination therapy. Beta-blockers are not first-line for primary hypertension without compelling indication (CAD, HFrEF, AF).

Question 12Internal medicine: physiology, differential diagnosis and clinical priorities

A 65-year-old man with COPD develops shortness of breath, chest pain, and tachycardia after a long flight. CT pulmonary angiogram confirms a segmental pulmonary embolism. He is hemodynamically stable. What is the most appropriate initial therapy?

  1. IV tPA (alteplase)
  2. Apixaban or rivaroxaban (a DOAC) as primary therapy Correct answer.
  3. IV heparin only with no oral transition
  4. Surgical embolectomy

Explanation

For hemodynamically stable PE, current guidelines recommend a DOAC (apixaban or rivaroxaban) as primary therapy without LMWH bridge for most patients. Both have built-in loading doses (apixaban 10 mg BID for 7 days then 5 mg BID; rivaroxaban 15 mg BID for 21 days then 20 mg daily). Duration is at least 3 months; longer for unprovoked or recurrent VTE.

Question 13Internal medicine: physiology, differential diagnosis and clinical priorities

A 30-year-old female teacher presents with chronic fatigue, dry eyes, dry mouth, and bilateral parotid gland enlargement. Schirmer test is positive. Anti-Ro (SSA) and anti-La (SSB) antibodies are positive. What is the most likely diagnosis?

  1. Sjogren syndrome Correct answer.
  2. Systemic lupus erythematosus
  3. Rheumatoid arthritis
  4. Behcet disease

Explanation

Sjogren syndrome is an autoimmune exocrinopathy presenting with sicca symptoms (dry eyes - keratoconjunctivitis sicca; dry mouth - xerostomia), parotid enlargement, and positive anti-Ro (SSA) and anti-La (SSB) antibodies. Primary Sjogren is isolated; secondary Sjogren accompanies RA, SLE, or other autoimmune disease. Increased risk of B-cell lymphoma. Treatment includes artificial tears, sialagogues, and immunomodulators for systemic involvement.

Question 14Internal medicine: physiology, differential diagnosis and clinical priorities

A 20-year-old male college athlete is found dead during football practice. Family history reveals two relatives died suddenly in their 30s. Autopsy shows asymmetric LV hypertrophy (septum to free wall ratio >2:1) and myofiber disarray. What is the most likely diagnosis?

  1. Long QT syndrome
  2. Hypertrophic cardiomyopathy Correct answer.
  3. Arrhythmogenic right ventricular cardiomyopathy (ARVC)
  4. Brugada syndrome

Explanation

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young athletes. It is characterized by asymmetric septal hypertrophy (>15 mm), LVOT obstruction in 25% (with systolic anterior motion of the mitral leaflet), and microscopic myocyte disarray on autopsy. Family history is positive in 50% (autosomal dominant; MYH7, MYBPC3 mutations). SCD risk factors include wall thickness >=30 mm, syncope, FHx SCD, NSVT, and abnormal BP response.

Question 15Internal medicine: physiology, differential diagnosis and clinical priorities

A 45-year-old man presents with episodes of sudden severe headache, palpitations, diaphoresis, and pallor. BP during episodes reaches 220/120. 24-hour urine metanephrines are markedly elevated. What is the next step in management?

  1. CT or MRI abdomen, then alpha blockade with phenoxybenzamine before beta blocker Correct answer.
  2. Immediate beta blockade
  3. Lifestyle modification only
  4. Genetic testing only

Explanation

Pheochromocytoma is diagnosed by elevated plasma free metanephrines or 24-hour urine metanephrines. After biochemical confirmation, CT or MRI of the abdomen localizes the tumor (90% adrenal, 10% extra-adrenal). Preoperative management requires alpha blockade FIRST (phenoxybenzamine 10-20 mg twice daily, titrating up) for 7-14 days, then beta blocker can be added. Starting beta blocker before alpha leads to unopposed alpha stimulation and hypertensive crisis.

Question 16Internal medicine: physiology, differential diagnosis and clinical priorities

A 30-year-old woman presents with intermittent flushing, watery diarrhea, wheezing, and right-sided heart valvular disease. Urine 5-HIAA is markedly elevated. What is the most likely diagnosis?

  1. Anaphylaxis from food allergy
  2. Carcinoid syndrome Correct answer.
  3. Hyperthyroidism
  4. Pheochromocytoma

Explanation

Carcinoid syndrome from a metastatic carcinoid tumor (usually small bowel with liver metastases) presents with flushing, secretory diarrhea, bronchospasm, and right-sided valvular heart disease (tricuspid regurgitation, pulmonary stenosis from serotonin-induced fibrosis). The lung filters serotonin, so left-sided valvular disease is rare. Diagnose with elevated 24-hour urine 5-HIAA. Treatment includes octreotide for symptoms and surgical resection of tumor.

Question 17Internal medicine: physiology, differential diagnosis and clinical priorities

A 40-year-old woman presents with progressive proximal muscle weakness and dysphagia. Examination shows shawl rash (V-neck distribution) and Gottron papules on the MCP and PIP joints. CK is elevated. What is the most likely diagnosis?

  1. Polymyositis
  2. Dermatomyositis Correct answer.
  3. Inclusion body myositis
  4. Steroid myopathy

Explanation

Dermatomyositis is characterized by proximal muscle weakness, elevated CK, and characteristic skin findings - Gottron papules (over knuckles), heliotrope rash (eyelids), shawl sign (V-distribution), and mechanic's hands (cracked fingers). Increased risk of malignancy (especially ovarian, breast, GI) - perform age-appropriate cancer screening. Treatment is high-dose corticosteroids plus steroid-sparing agents (methotrexate, azathioprine).

Question 18Internal medicine: physiology, differential diagnosis and clinical priorities

A 25-year-old presents with abdominal pain, hemoptysis, and pulmonary infiltrates. UA shows red cell casts and proteinuria. Anti-glomerular basement membrane (anti-GBM) antibody is positive. What is the most likely diagnosis?

  1. IgA nephropathy
  2. Goodpasture syndrome (anti-GBM disease) Correct answer.
  3. Granulomatosis with polyangiitis (GPA)
  4. Lupus nephritis

Explanation

Goodpasture syndrome (anti-GBM antibody disease) is a small-vessel vasculitis with autoantibodies against the alpha-3 chain of type IV collagen in the alveolar and glomerular basement membranes. It presents with diffuse alveolar hemorrhage (hemoptysis, dyspnea) and rapidly progressive glomerulonephritis (proteinuria, hematuria with red cell casts, AKI). Treatment is plasmapheresis to remove the antibody, plus corticosteroids and cyclophosphamide.

Question 19Internal medicine: physiology, differential diagnosis and clinical priorities

A 50-year-old man presents to a primary care clinic with snoring, witnessed apneas, and daytime somnolence (Epworth score 18). His BMI is 35. Polysomnography shows AHI of 35. What is the most appropriate first-line treatment?

  1. CPAP at therapeutic pressure Correct answer.
  2. Oral appliance only
  3. Tracheostomy
  4. Modafinil monotherapy

Explanation

Severe OSA (AHI >=30 or moderate with significant symptoms) is treated first-line with CPAP titrated to abolish events. Mild-moderate OSA may use mandibular advancement oral appliances. Weight loss, positional therapy, and avoidance of alcohol/sedatives are adjuncts. Hypoglossal nerve stimulation (Inspire) is reserved for CPAP-intolerant patients with AHI 15-65 and BMI <32. Tracheostomy is for refractory severe disease.

Question 20Internal medicine: physiology, differential diagnosis and clinical priorities

A 20-year-old man with type 1 diabetes is found unresponsive at home. Glucose 30 mg/dL. After IV dextrose administration, he becomes alert. Investigation reveals he had been adjusting his insulin dose without checking glucose. What is the most appropriate long-term management?

  1. Decrease insulin dose substantially
  2. Comprehensive diabetes education plus CGM (continuous glucose monitor) Correct answer.
  3. Switch to oral hypoglycemic agents
  4. Stop insulin entirely

Explanation

Hypoglycemia management in type 1 diabetes includes acute glucose administration, comprehensive education on insulin adjustment, recognition of hypoglycemia, and consideration of CGM (continuous glucose monitor) to detect trends and warn of impending hypoglycemia. Dexcom and Libre CGMs significantly reduce severe hypoglycemia events. Endocrine referral for insulin pump or hybrid closed-loop systems may also be appropriate.

Question 21Internal medicine: physiology, differential diagnosis and clinical priorities

A 40-year-old man presents with hyperpigmented, velvety thickening on the back of his neck and in his axillae. He has a strong family history of type 2 diabetes. What is the most likely diagnosis?

  1. Tinea versicolor
  2. Acanthosis nigricans (often associated with insulin resistance) Correct answer.
  3. Eczema
  4. Erythrasma

Explanation

Acanthosis nigricans is a dermatologic marker of insulin resistance, often present in patients with metabolic syndrome and type 2 diabetes risk. It presents as hyperpigmented, velvety, thickened skin in skin folds (neck, axillae, groin). Treatment focuses on the underlying cause (weight loss, glucose control). Sudden onset in older adults raises concern for paraneoplastic syndrome (gastric adenocarcinoma).

Question 22Internal medicine: physiology, differential diagnosis and clinical priorities

A 70-year-old woman presents with progressive bone pain, fatigue, and recurrent infections. Labs show calcium 11.8, hemoglobin 9.0, creatinine 2.5, and a monoclonal IgG spike on SPEP. Bone marrow biopsy shows 15% plasma cells. What is the most likely diagnosis?

  1. Multiple myeloma Correct answer.
  2. Monoclonal gammopathy of undetermined significance (MGUS)
  3. Waldenstrom macroglobulinemia
  4. Smoldering myeloma

Explanation

Multiple myeloma is diagnosed by the CRAB criteria - hyperCalcemia, Renal insufficiency, Anemia, Bone disease (lytic lesions, fractures) - PLUS >10% clonal plasma cells in bone marrow or biopsy-proven plasmacytoma. Workup includes SPEP/UPEP, serum free light chains, beta-2 microglobulin, and skeletal survey or PET-CT. Treatment is risk-stratified and includes proteasome inhibitors (bortezomib), IMiDs (lenalidomide), monoclonal antibodies (daratumumab), and consideration of autologous stem cell transplantation.

Question 23Internal medicine: physiology, differential diagnosis and clinical priorities

A 65-year-old man with COPD on home oxygen develops worsening dyspnea, wheezing, and increased sputum production. Vital signs: HR 110, RR 28, SpO2 86% on his usual 2 L/min. ABG shows pH 7.30, pCO2 65, pO2 55. What is the appropriate management?

  1. Increase oxygen to maintain SpO2 88-92%, IV/PO corticosteroids, bronchodilators, antibiotics, and consider NIV (BiPAP) Correct answer.
  2. Intubate immediately
  3. Decrease oxygen flow to drop PCO2
  4. Discharge with PO antibiotics only

Explanation

Acute COPD exacerbation with respiratory acidosis (pH <7.35 with hypercarbia) is managed with: target SpO2 88-92% (NOT >94% - risks worsening hypercarbia from hypoxic vasoconstriction reversal and Haldane effect), inhaled bronchodilators (albuterol/ipratropium nebs), systemic corticosteroids (prednisone 40 mg or methylprednisolone 1 mg/kg), antibiotics if increased sputum purulence or mechanical ventilation, and BiPAP for moderate-to-severe acidosis to reduce intubation. Intubate if BiPAP fails or contraindicated.

Question 24Internal medicine: physiology, differential diagnosis and clinical priorities

A 25-year-old develops a rash 1 week after starting trimethoprim-sulfamethoxazole for a UTI. The rash is initially morbilliform but evolves into painful blisters with sloughing involving 15% of body surface area, oral mucosa, and conjunctiva. What is the most likely diagnosis?

  1. Allergic contact dermatitis
  2. Stevens-Johnson syndrome (SJS) / Toxic epidermal necrolysis (TEN) spectrum Correct answer.
  3. Erythema multiforme
  4. Bullous pemphigoid

Explanation

Stevens-Johnson syndrome (<10% BSA) and toxic epidermal necrolysis (>30% BSA) are severe mucocutaneous drug reactions with epidermal necrosis, painful blisters, mucositis (oral, ocular, genital), and positive Nikolsky sign. Common triggers: sulfa drugs (TMP-SMX), anticonvulsants (lamotrigine, carbamazepine, phenytoin), allopurinol. Management: STOP the offending drug, ICU/burn unit supportive care, IV fluids, wound care, ophthalmology consult, IVIG or cyclosporine.

Question 25Internal medicine: physiology, differential diagnosis and clinical priorities

A 30-year-old presents with painless yellow-orange waxy plaques on the eyelids. Lipid panel reveals total cholesterol 350, LDL 250, HDL 35. Family history of premature CAD. What is the most likely diagnosis?

  1. Familial hypercholesterolemia with xanthelasma Correct answer.
  2. Acanthosis nigricans
  3. Pemphigus vulgaris
  4. Sebaceous cyst

Explanation

Xanthelasma palpebrarum (yellow-orange waxy plaques on eyelids) is a common cutaneous marker of dyslipidemia, especially familial hypercholesterolemia (FH). FH (autosomal dominant LDLR, ApoB, or PCSK9 mutations) typically presents with LDL >190 in adults, early CAD, tendinous xanthomas, and corneal arcus. Treatment: high-intensity statin (atorvastatin 40-80, rosuvastatin 20-40) plus ezetimibe; PCSK9 inhibitor (alirocumab/evolocumab) for refractory cases.

Question 26Internal medicine: physiology, differential diagnosis and clinical priorities

A 65-year-old man with COPD and frequent exacerbations develops new symptoms: cough productive of bloody sputum, weight loss 15 lb in 3 months, and a 3-cm mass in the right hilum on CXR. He has a 60-pack-year smoking history. What is the next diagnostic step?

  1. Repeat CXR in 3 months
  2. CT chest with contrast and tissue biopsy (bronchoscopy or CT-guided) Correct answer.
  3. Annual screening only
  4. Sputum cytology alone

Explanation

Suspected lung cancer with hilar mass and weight loss requires urgent CT chest with contrast for staging, followed by tissue diagnosis (bronchoscopy with biopsy/brushings if central; CT-guided needle biopsy if peripheral; or VATS biopsy if other approaches fail). PET-CT for staging once diagnosis is confirmed. Mediastinoscopy or EBUS may be needed for lymph node staging. Molecular testing (EGFR, ALK, ROS1, BRAF, PD-L1) and immunotherapy considerations follow histologic diagnosis.

Question 27Internal medicine: physiology, differential diagnosis and clinical priorities

A 22-year-old college student presents with a 3-week history of high-grade fever, fatigue, splenomegaly, and a generalized lymphadenopathy. Heterophile antibody test (Monospot) is positive. Atypical lymphocytes are seen on peripheral smear. What is the most likely diagnosis and management?

  1. Acute leukemia - immediate chemotherapy
  2. Infectious mononucleosis (EBV) - supportive care, avoid contact sports for 4 weeks Correct answer.
  3. HIV seroconversion - start antiretroviral therapy
  4. Cytomegalovirus mononucleosis - antiviral therapy

Explanation

Infectious mononucleosis from Epstein-Barr virus (EBV) classically presents with high-grade fever, fatigue, splenomegaly, generalized lymphadenopathy, atypical lymphocytes on smear, and positive heterophile antibody (Monospot). Management is supportive - rest, hydration, NSAIDs/acetaminophen, avoid contact sports for at least 3-4 weeks due to splenic rupture risk. Glucocorticoids may help if severe airway obstruction. Avoid amoxicillin (causes morbilliform rash in EBV infection).

Question 28Surgical assessment, trauma and anatomical complications

A 19-year-old presents to the ED with 3 hours of severe right lower quadrant pain, nausea, and one episode of emesis. McBurney's point tenderness is positive. WBC 14,000 with left shift. Beta-hCG negative. What is the most appropriate imaging?

  1. KUB X-ray
  2. Abdominal CT with contrast Correct answer.
  3. Abdominal MRI
  4. No imaging - proceed directly to surgery

Explanation

In adults with suspected appendicitis, abdominal/pelvic CT with IV contrast is the imaging of choice (sensitivity ~95%, specificity ~95%). Ultrasound is first-line in children and pregnant women due to radiation concerns. Some surgeons proceed directly to surgery in high-probability cases without imaging, but CT confirmation is now standard practice and avoids unnecessary appendectomy.

Question 29Surgical assessment, trauma and anatomical complications

A 75-year-old man on warfarin for AF falls and develops bilateral subdural hematomas on CT. He is on warfarin. INR is 3.2. What is the most appropriate immediate reversal?

  1. IV vitamin K 10 mg plus 4-factor prothrombin complex concentrate (4F-PCC) Correct answer.
  2. Oral vitamin K 5 mg only
  3. FFP 6 units only
  4. Idarucizumab

Explanation

Life-threatening warfarin-related bleeding (e.g., intracranial hemorrhage) requires immediate reversal with 4-factor prothrombin complex concentrate (Kcentra; 25-50 units/kg) PLUS IV vitamin K (10 mg slow infusion). 4F-PCC reverses INR within minutes; vitamin K provides sustained reversal as PCC effects wane after ~6 hours. FFP is an alternative if 4F-PCC is unavailable but is slower and requires larger volumes.

Question 30Surgical assessment, trauma and anatomical complications

A 50-year-old construction worker with diabetes presents with painful, swollen, red skin on his right lower leg with rapid progression and crepitus on palpation. He has bullae and is febrile (39.2 C). What is the most likely diagnosis and management?

  1. Cellulitis with oral antibiotics
  2. Necrotizing fasciitis with emergent surgical debridement and IV broad-spectrum antibiotics Correct answer.
  3. Lymphedema with elevation
  4. Deep vein thrombosis with anticoagulation

Explanation

Necrotizing fasciitis (Type 1 polymicrobial in diabetics; Type 2 group A strep monomicrobial) is a surgical emergency. Clues: severe pain out of proportion to exam, rapid spread, crepitus, bullae, systemic toxicity. Management: emergent surgical debridement plus broad-spectrum IV antibiotics (vancomycin + piperacillin-tazobactam + clindamycin for toxin suppression). Diagnostic LRINEC score >=6 raises suspicion. Mortality 25-30% even with treatment.

Question 31Surgical assessment, trauma and anatomical complications

A 45-year-old woman presents with intermittent right upper quadrant pain after fatty meals and ultrasound confirms gallstones. She is currently asymptomatic. What is the most appropriate next step?

  1. Elective cholecystectomy because she is symptomatic from cholelithiasis Correct answer.
  2. Open cholecystectomy
  3. Ursodeoxycholic acid only
  4. No intervention; observe

Explanation

Symptomatic gallstones (biliary colic = postprandial RUQ pain) are an indication for elective laparoscopic cholecystectomy. Asymptomatic gallstones in non-diabetic patients are usually observed (asymptomatic gallstones in diabetics, sickle cell, or post-transplant may also be operated on). Open cholecystectomy is reserved for complicated cases. Ursodeoxycholic acid dissolves small cholesterol stones slowly and is reserved for surgical candidates who decline surgery.

Question 32Pediatric reasoning: development, illness severity and age-specific assessment

A 4-year-old presents with barking cough, inspiratory stridor at rest, and mild retractions. Temperature is 38.5 C. He is alert and not toxic-appearing. What is the best initial management?

  1. IM ceftriaxone and admission
  2. Single dose of oral dexamethasone and nebulized racemic epinephrine Correct answer.
  3. Albuterol nebulizer and discharge
  4. Cool mist therapy and discharge home

Explanation

Moderate croup (stridor at rest with retractions) requires a single dose of dexamethasone (0.6 mg/kg PO/IM/IV) plus nebulized racemic epinephrine. Observe for 3-4 hours after epinephrine for rebound stridor before discharge. Severe disease (cyanosis, exhaustion, altered mental status) requires admission and possible airway support.

Question 33Pediatric reasoning: development, illness severity and age-specific assessment

A 6-year-old child with autism is being managed for severe aggression and self-injurious behavior. After behavioral interventions, an antipsychotic is considered. Which medication is FDA-approved for autism-associated irritability?

  1. Risperidone Correct answer.
  2. Methylphenidate
  3. Fluoxetine
  4. Lithium

Explanation

Risperidone has an FDA indication for irritability associated with autistic disorder in the relevant pediatric age range. Use still requires an individualized assessment, behavioral support and monitoring for metabolic, neurological and other adverse effects.

Question 34Pediatric reasoning: development, illness severity and age-specific assessment

A 5-year-old with poorly controlled type 1 diabetes presents with abdominal pain, vomiting, and Kussmaul respirations. Labs show glucose 480, pH 7.18, bicarbonate 8, anion gap 24. What is the FIRST step in management?

  1. IV insulin bolus
  2. IV normal saline bolus Correct answer.
  3. IV bicarbonate infusion
  4. Subcutaneous insulin

Explanation

DKA management starts with fluid resuscitation (10-20 mL/kg bolus of normal saline) to restore intravascular volume before insulin is initiated. Insulin drip (0.05-0.1 units/kg/hour) follows once fluids have begun, ideally with hourly glucose monitoring and addition of dextrose when glucose drops to ~250 mg/dL. Potassium is monitored carefully - replace once K <5.2-5.5 to avoid hypokalemia as insulin drives K intracellularly.

Question 35Pediatric reasoning: development, illness severity and age-specific assessment

A 6-year-old presents with high fever, conjunctival injection, strawberry tongue, cervical lymphadenopathy, erythema of palms and soles, and rash for 5 days. What is the most likely diagnosis and treatment?

  1. Scarlet fever - treat with amoxicillin
  2. Kawasaki disease - treat with IVIG and high-dose aspirin Correct answer.
  3. Toxic shock syndrome - treat with vasopressors
  4. Measles - supportive care only

Explanation

Kawasaki disease is diagnosed by fever >5 days plus >=4 of: bilateral conjunctival injection (limbic sparing), oral changes (strawberry tongue, cracked lips), rash (polymorphic), cervical lymphadenopathy >1.5 cm, and extremity changes (erythema of palms/soles, peeling). Treatment is IVIG 2 g/kg single dose plus high-dose aspirin to prevent coronary aneurysms (the most feared complication). Echo at diagnosis, 2 weeks, and 6-8 weeks.

Question 36Pediatric reasoning: development, illness severity and age-specific assessment

An 18-month-old presents with progressive lethargy, irritability, and a palpable abdominal mass crossing the midline. Imaging reveals a heterogeneous mass arising from the adrenal gland with calcifications. Urine catecholamines are elevated. What is the most likely diagnosis?

  1. Wilms tumor
  2. Neuroblastoma Correct answer.
  3. Pheochromocytoma
  4. Rhabdomyosarcoma

Explanation

Neuroblastoma is the most common extracranial solid tumor in children <5 years, arising from neural crest cells in the adrenal gland or sympathetic chain. Presentation: abdominal mass crossing the midline (Wilms tumor typically does not cross midline), bone pain from metastases, raccoon eyes (orbital metastases), and elevated urine catecholamines (HVA, VMA). MYCN amplification is a poor prognostic marker.

Question 37Pediatric reasoning: development, illness severity and age-specific assessment

A 5-day-old neonate presents with poor feeding, lethargy, and a generalized seizure. Labs show ammonia 800 (normal <50), normal glucose, and respiratory alkalosis. Plasma amino acids are pending. What is the most likely diagnosis?

  1. Urea cycle disorder Correct answer.
  2. Hypoglycemia
  3. Sepsis with meningitis
  4. Hypocalcemia

Explanation

Urea cycle disorders (most commonly OTC deficiency, X-linked) present in neonates with severe hyperammonemia (often >500-1000 mcg/dL), respiratory alkalosis (ammonia stimulates respiration), poor feeding, lethargy, seizures, and progress to coma. Treatment: discontinue protein, dextrose-electrolyte solutions, ammonia scavengers (sodium phenylbutyrate, glycerol phenylbutyrate), and emergent hemodialysis. Genetic and dietary management long-term.

Question 38Pediatric reasoning: development, illness severity and age-specific assessment

A 5-year-old presents with mild respiratory distress, expiratory wheeze, and a peak flow 70% of personal best. He has known mild persistent asthma on daily ICS. What is the most appropriate initial management of this acute exacerbation?

  1. Albuterol nebulizer plus oral corticosteroids (e.g., prednisolone) Correct answer.
  2. IV magnesium sulfate alone
  3. Intubation
  4. Bronchoscopy

Explanation

Mild-moderate asthma exacerbation: albuterol via nebulizer or MDI with spacer (every 20 minutes x 3 then reassess) plus systemic corticosteroids (oral prednisolone or dexamethasone). For pediatric patients, dexamethasone 0.6 mg/kg (max 16 mg) PO single or 2-day dose is increasingly preferred over 5-day prednisolone. Continue inhaled corticosteroids. Reassess every 1 hour. Hospitalize if poor response or peak flow <50%.

Question 39Obstetric and gynecological assessment and clinical priorities

A 32-week pregnant woman presents with BP 165/110, headache, and urine dipstick showing 3+ proteinuria. She has hyperreflexia and clonus. What is the first-line treatment to prevent eclamptic seizures?

  1. IV magnesium sulfate Correct answer.
  2. Oral nifedipine
  3. IV diazepam
  4. IV phenytoin

Explanation

This patient has severe preeclampsia with features (BP >=160/110, hyperreflexia, clonus). IV magnesium sulfate is the first-line seizure prophylaxis and has superior efficacy to phenytoin and diazepam (MAGPIE and Collaborative Eclampsia Trial). Therapeutic level is 4-7 mg/dL; monitor for loss of patellar reflex, respiratory depression, and oliguria. IV calcium gluconate is the antidote.

Question 40Obstetric and gynecological assessment and clinical priorities

A 28-year-old G2P1 at 36 weeks gestation presents with painless vaginal bleeding. Speculum exam reveals blood in the vault. What is the next best step?

  1. Immediate digital cervical examination
  2. Transabdominal ultrasound for placental location Correct answer.
  3. Emergent cesarean delivery
  4. Induction with oxytocin

Explanation

Painless third-trimester vaginal bleeding is concerning for placenta previa. Transabdominal ultrasound must be performed BEFORE digital cervical examination to localize the placenta, as digital exam can precipitate massive hemorrhage if previa is present. Once previa is excluded, digital exam may proceed cautiously.

Question 41Obstetric and gynecological assessment and clinical priorities

A 28-year-old G1P0 at 28 weeks gestation has a positive 1-hour glucose challenge test (155 mg/dL). Three-hour GTT confirms gestational diabetes. After lifestyle modification fails, what is the first-line pharmacotherapy?

  1. Glipizide
  2. Insulin Correct answer.
  3. Pioglitazone
  4. Sitagliptin

Explanation

Insulin remains the first-line pharmacotherapy for gestational diabetes when lifestyle measures fail because it does not cross the placenta, has the most evidence in pregnancy, and allows tight glycemic control. Metformin is an acceptable alternative (crosses the placenta but does not appear teratogenic). Glipizide and other oral hypoglycemics have less safety data in pregnancy.

Question 42Obstetric and gynecological assessment and clinical priorities

A 24-year-old presents with a positive home pregnancy test. Her last period was 7 weeks ago. She develops sudden onset right lower quadrant pain and lightheadedness. Bedside ultrasound shows free fluid in the pelvis with no intrauterine pregnancy seen. Quantitative beta-hCG is 2,800 mIU/mL. What is the most likely diagnosis?

  1. Threatened abortion
  2. Ectopic pregnancy Correct answer.
  3. Ovarian cyst rupture
  4. Appendicitis

Explanation

An ectopic pregnancy is the most likely diagnosis: beta-hCG >1,500-2,000 mIU/mL (discriminatory zone) without an intrauterine pregnancy on transvaginal US, with free pelvic fluid and acute pain, strongly suggests ectopic. Management depends on size, location, and stability - methotrexate IM for small, stable, unruptured ectopics; surgery (laparoscopy) for ruptured/unstable or those with contraindications to methotrexate.

Question 43Obstetric and gynecological assessment and clinical priorities

A 28-year-old woman 12 weeks postpartum presents with painful, swollen, red right breast. She reports breastfeeding pain. Examination shows induration without fluctuance. Temperature is 38.5 C. What is the most appropriate initial treatment?

  1. Discontinue breastfeeding and surgical incision and drainage
  2. Continue breastfeeding and start dicloxacillin (or cephalexin) Correct answer.
  3. Cold compress only
  4. Oral corticosteroids

Explanation

Postpartum mastitis is typically caused by Staphylococcus aureus and presents with localized erythema, induration, fever, and breast pain. Treatment is continued breastfeeding (to maintain drainage) plus oral antistaphylococcal antibiotic (dicloxacillin, cephalexin; or clindamycin if MRSA suspected). Cessation of breastfeeding worsens outcomes by causing milk stasis. Incision and drainage is reserved for established abscess (fluctuance on exam).

Question 44Obstetric and gynecological assessment and clinical priorities

A 28-year-old G2P1 at 38 weeks gestation has been in active labor for 4 hours with full dilation. After uterine atony develops postpartum, she has 1.5 L of blood loss in 30 minutes. After uterine massage, IV oxytocin, and IM methylergonovine, bleeding continues. What is the next step?

  1. Tranexamic acid (TXA) IV
  2. Bakri balloon tamponade and consideration of uterine artery embolization or hysterectomy if bleeding continues Correct answer.
  3. Wait 1 hour before further intervention
  4. Discontinue all uterotonics

Explanation

Postpartum hemorrhage from uterine atony is managed stepwise: bimanual uterine massage, IV oxytocin (40 units in 1 L NS or LR over 10 min), IM methylergonovine (avoid in HTN), IM carboprost (avoid in asthma), misoprostol (rectal 800-1000 mcg), IV TXA. If pharmacologic management fails, mechanical methods (Bakri balloon, uterine packing) and surgical interventions (uterine artery embolization, B-Lynch suture, internal iliac ligation, hysterectomy) are next.

Question 45Obstetric and gynecological assessment and clinical priorities

A 35-year-old G3P2 woman 12 weeks postpartum presents with persistent fatigue, weight loss, palpitations, and heat intolerance. Her TSH is 0.05 mIU/L and free T4 is 2.5 ng/dL. Anti-TPO antibodies are markedly elevated. What is the most likely diagnosis?

  1. Graves disease
  2. Postpartum thyroiditis (hyperthyroid phase) Correct answer.
  3. Thyroid storm
  4. Iatrogenic thyrotoxicosis

Explanation

Postpartum thyroiditis occurs in 5-10% of women within the first year postpartum, typically with a classic biphasic pattern: hyperthyroid phase (1-6 months postpartum) due to thyroid hormone leak, followed by hypothyroid phase (3-12 months) due to depletion of stores, then usually recovery (although 20-40% develop permanent hypothyroidism). Treatment in hyperthyroid phase is symptomatic (beta-blocker for palpitations); ATA recommends NOT treating with antithyroid drugs as the process is self-limited. Anti-TPO antibodies are typically elevated.

Question 46Neurological and psychiatric clinical reasoning

A 28-year-old presents with hopelessness, anhedonia, and insomnia for 4 weeks. PHQ-9 score is 18. She admits to passive suicidal ideation without plan. Which is the most appropriate first-line pharmacotherapy?

  1. Lithium 600 mg twice daily
  2. Sertraline 50 mg daily Correct answer.
  3. Risperidone 2 mg daily
  4. Lorazepam 1 mg three times daily

Explanation

Moderate-to-severe major depressive disorder (PHQ-9 15-19 moderate, >=20 severe) responds to first-line SSRIs such as sertraline, escitalopram, or fluoxetine. Sertraline 50 mg daily is a standard starting dose with titration to therapeutic effect in 4-6 weeks. The black box warning regarding suicidality in patients <25 mandates close monitoring during the first 1-2 weeks.

Question 47Neurological and psychiatric clinical reasoning

A 45-year-old chronic alcoholic presents with confusion, ataxia, and ophthalmoplegia. His blood glucose is 75 mg/dL. What should be administered FIRST?

  1. IV dextrose
  2. IV thiamine Correct answer.
  3. IV magnesium sulfate
  4. IV haloperidol

Explanation

The neurological pattern suggests Wernicke encephalopathy and warrants prompt parenteral thiamine. If dangerous hypoglycemia is also present, necessary glucose must not be delayed while waiting for thiamine.

Question 48Neurological and psychiatric clinical reasoning

A 19-year-old college student presents with low-grade fever, headache, and a stiff neck. Lumbar puncture reveals: WBC 250 (95% lymphocytes), glucose 60 (serum 90), protein 65, gram stain negative. What is the most likely diagnosis?

  1. Bacterial meningitis
  2. Viral (aseptic) meningitis Correct answer.
  3. Fungal meningitis
  4. Tuberculous meningitis

Explanation

CSF with lymphocytic predominance, normal glucose, mildly elevated protein, and negative gram stain is consistent with viral (aseptic) meningitis (most commonly enterovirus). Bacterial meningitis shows neutrophilic predominance, low glucose (<40 or CSF:serum <0.4), and very high protein. Treatment is supportive; empiric antibiotics may be given until cultures return.

Question 49Neurological and psychiatric clinical reasoning

A 55-year-old man presents with a 2-week history of progressive ascending weakness, areflexia, and tingling in his hands and feet, beginning 3 weeks after a respiratory infection. CSF shows elevated protein with normal cell count (albuminocytologic dissociation). What is the most likely diagnosis and treatment?

  1. ALS - supportive care only
  2. Guillain-Barre syndrome - IVIG or plasmapheresis Correct answer.
  3. Multiple sclerosis - high-dose steroids
  4. Myasthenia gravis - pyridostigmine

Explanation

Guillain-Barre syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy presenting with ascending weakness and areflexia, often following a respiratory or GI infection (Campylobacter most common). CSF shows albuminocytologic dissociation. Treatment is IVIG (2 g/kg over 2-5 days) or plasmapheresis; corticosteroids are NOT beneficial. Monitor respiratory function (FVC, peak inspiratory force) and intubate if FVC <20 mL/kg.

Question 50Neurological and psychiatric clinical reasoning

A 28-year-old woman presents with sudden onset facial droop, weakness, and slurred speech. Last known normal was 90 minutes ago. NIHSS is 12. CT head shows no hemorrhage. CT angiography shows occlusion of the right M1 segment. What is the most appropriate management?

  1. IV tPA (alteplase) plus mechanical thrombectomy Correct answer.
  2. Aspirin 325 mg orally
  3. Watch and wait for spontaneous recovery
  4. Anticoagulation with heparin

Explanation

Acute ischemic stroke with large vessel occlusion (LVO; M1, ICA, basilar) within 4.5 hours of last known well: IV tPA 0.9 mg/kg (max 90 mg, 10% bolus then infusion over 60 min) PLUS mechanical thrombectomy if presented within 24 hours of LKW (DAWN/DEFUSE-3 trials extended window for select patients with favorable imaging). This patient is at 90 minutes - well within both windows.