Browse all 250 questions with explanations
A 4-week-old infant is brought with progressive jaundice, dark urine, and acholic stools since 2 weeks of age. On examination, the liver is firm and enlarged 4 cm below the costal margin. Ultrasound shows a triangular cord sign measuring 5 mm. What is the most appropriate next step in management?
Which of the following is the most sensitive and specific ultrasonographic finding for biliary atresia in a cholestatic infant?
An infant with biliary atresia undergoes a successful Kasai portoenterostomy at 45 days of life. Which factor most strongly predicts a good long-term outcome with native liver survival?
A 3-week-old infant presents with jaundice. Laboratory studies show: total bilirubin 12 mg/dL, direct bilirubin 8 mg/dL, AST 120 U/L, ALT 98 U/L, GGT 450 U/L. What is the most likely diagnosis?
Which of the following conditions is the most common cause of neonatal cholestasis?
A neonate with biliary atresia is being evaluated for Kasai portoenterostomy. Which preoperative finding suggests advanced disease and a poorer prognosis?
In an infant with suspected biliary atresia, which of the following is the gold standard for establishing the diagnosis?
A 6-week-old infant with biliary atresia is being considered for liver transplantation. Which of the following is the most common indication for proceeding to transplant after Kasai?
Which viral infection is most commonly associated with the embryonic form of biliary atresia?
A 1-month-old infant with cholestasis is found to have polysplenia and situs inversus. Which biliary anomaly should be strongly suspected?
A 2-day-old newborn develops bilious vomiting and abdominal distension. On examination, the abdomen is scaphoid. A nasogastric tube yields bilious aspirate. What is the most appropriate immediate next step?
A newborn with bilious vomiting is found to have a 'double bubble' sign on abdominal X-ray with no distal gas. What is the most likely diagnosis?
An infant with bilious vomiting undergoes an upper GI contrast study which shows the duodenojejunal flexure to the right of the spine and below the pylorus, with a corkscrew appearance of the duodenum and jejunum. What is the diagnosis?
A term infant fails to pass meconium within 48 hours of birth and develops progressive abdominal distension and bilious vomiting. Rectal examination reveals a tight anal canal with explosive stool discharge. What is the definitive diagnostic test?
Which of the following is the most common site of aganglionosis in Hirschsprung disease?
A newborn with jejunal atresia undergoes laparotomy. The surgeon finds multiple atretic segments resembling a 'string of sausages.' Which embryological mechanism is most likely responsible?
A 3-day-old infant is diagnosed with malrotation. During the Ladd procedure, what is the most critical step to prevent recurrent volvulus?
A newborn with cystic fibrosis presents with meconium ileus. On abdominal X-ray, there are bubbly or granular appearances in the right lower quadrant due to trapped air in thick meconium. What is this sign called?
A neonate with meconium ileus fails to respond to water-soluble contrast enema. Laparotomy reveals a segment of ileum that is markedly dilated and filled with thick meconium, with a microcolon. Which intraoperative procedure is most appropriate?
Which of the following is the most serious early complication of untreated midgut volvulus in a neonate?
A 4-month-old infant presents with frequent regurgitation, irritability during feeds, and poor weight gain. There is no bilious vomiting. Which of the following is the first-line management?
An adolescent with chronic abdominal pain is diagnosed with peptic ulcer disease. Testing for Helicobacter pylori is positive. Which is the most appropriate first-line eradication regimen?
A 12-year-old with recurrent oral ulcers, abdominal pain, bloody diarrhea, and weight loss is diagnosed with Crohn disease. Colonoscopy reveals skip lesions, cobblestoning, and transmural inflammation. Which extraintestinal manifestation is most commonly associated with this condition?
A 10-year-old with ulcerative colitis has been in remission on mesalamine for 2 years. During a routine visit, which test is most important for long-term surveillance?
A 3-year-old with chronic diarrhea, failure to thrive, and abdominal distension has a tissue transglutaminase (tTG) IgA level of 120 U/mL (normal <10). What is the next best step to confirm celiac disease?
Which serological marker has the highest sensitivity and specificity for diagnosing celiac disease in children older than 2 years?
A child with Crohn disease fails to respond to corticosteroids and mesalamine. Which biologic agent is most appropriate as the next step?
Which complication of GERD in infants is the strongest indication for performing a Nissen fundoplication?
A 14-year-old with ulcerative colitis presents with severe bloody diarrhea (>8 stools/day), fever 39 C, tachycardia, and anemia (Hb 7.2 g/dL). The CRP is 45 mg/L. What is the most appropriate immediate management?
A child with celiac disease has been strictly gluten-free for 6 months but continues to have elevated tTG IgA antibodies and persistent symptoms. Which is the most common cause of non-responsive celiac disease?
A 9-month-old infant is brought with acute watery diarrhea for 2 days and moderate dehydration (skin pinch returns in 2 seconds, restless, irritable). According to WHO guidelines, which plan should be implemented?
According to the WHO low-osmolarity ORS formula, what is the sodium concentration (in mmol/L)?
A 10-month-old with acute diarrhea is being managed at home. According to WHO and IAP guidelines, what is the correct zinc supplementation regimen?
A 2-year-old with severe acute watery diarrhea is lethargic, has sunken eyes, a skin pinch that returns in 3 seconds, and is unable to drink. What is the first-line fluid management according to WHO Plan C?
During the management of acute diarrhea, which of the following is an absolute contraindication to giving ORS?
A 6-month-old with acute watery diarrhea has the following serum electrolytes: Na 152 mEq/L, K 3.2 mEq/L, Cl 110 mEq/L. Which type of dehydration is most likely present?
Which of the following correctly describes the glucose-to-sodium ratio in WHO low-osmolarity ORS, and why is it important?
A 1-year-old with acute diarrhea is given ORS at home under Plan A. The mother asks when she should return to the health facility. Which of the following is NOT a danger sign requiring immediate return?
A 5-month-old infant with acute diarrhea and some dehydration is being rehydrated with ORS. When should the mother resume feeding?
A child with acute diarrhea is treated with ORS and zinc. The mother asks if antimotility agents like loperamide can be given. What is the correct advice?
A 7-year-old child presents with jaundice, dark urine, and pale stools. Serology shows anti-HAV IgM positive, anti-HAV IgG negative. What is the most likely clinical course?
A newborn is born to an HBsAg-positive mother. Which is the most effective intervention to prevent mother-to-child transmission?
An adolescent with acute liver failure presents with confusion, asterixis, and a declining Glasgow Coma Scale. Which grade of hepatic encephalopathy is most consistent with these findings?
A 15-year-old with acute liver failure (INR 3.5, ammonia 180 micromol/L) develops cerebral edema. Which of the following is the most important immediate intervention to reduce intracranial pressure?
Which of the following is the most common cause of acute liver failure in children in developing countries like India?
A 12-year-old with Wilson disease presents with acute hemolysis, Coombs-negative anemia, and acute liver failure. Which biochemical finding is most characteristic?
Which of the following is the most sensitive test to detect chronic hepatitis B infection in a child?
A child with chronic hepatitis B and active replication (HBeAg positive, HBV DNA >20,000 IU/mL, elevated ALT) is being considered for treatment. Which is the preferred first-line oral antiviral agent in children?
Which of the following clinical signs is most specific for hepatic encephalopathy in a child with acute liver failure?
A 6-year-old with acute liver failure develops progressive coagulopathy (INR 4.5), encephalopathy grade III, and anuria. Which criterion makes liver transplantation most urgently indicated?
A 10-year-old with chronic liver disease presents with hematemesis. Endoscopy reveals large esophageal varices with red whale markings and active bleeding. What is the most appropriate immediate endoscopic therapy?
After controlling an acute variceal bleed with EVL in a child with portal hypertension, which pharmacological agent is most appropriate for secondary prophylaxis?
A child with portal hypertension develops recurrent ascites resistant to diuretics. Which procedure is most appropriate for long-term management?
Which of the following is the most common cause of portal hypertension in children?
A child with known portal hypertension presents with a massive upper GI bleed. The hemoglobin is 5.8 g/dL, and the child is hemodynamically unstable. What is the correct sequence of immediate management?
A child with extrahepatic portal vein obstruction (EHPVO) has recurrent variceal bleeds despite two sessions of EVL. Which surgical procedure is most appropriate?
Which of the following is the primary goal of primary prophylaxis in a child with large esophageal varices but no history of bleeding?
A child with cirrhosis and portal hypertension develops thrombocytopenia (platelets 60,000/mcL) but no active bleeding. What is the most likely mechanism?
In a child with acute variceal bleeding, which vasoactive agent acts by causing splanchnic vasoconstriction through V1 receptor agonism?
A child with portal hypertension is found to have gastric varices without esophageal varices. Which endoscopic treatment is most effective for gastric variceal bleeding?
An 8-year-old presents with severe epigastric pain radiating to the back, vomiting, and fever. Serum lipase is 1200 U/L (normal <60). What is the most common etiology of acute pancreatitis in children?
Which of the following is the most specific and sensitive enzyme for diagnosing acute pancreatitis in children?
A newborn with meconium ileus is found to have a mutation in the CFTR gene. Which is the earliest gastrointestinal manifestation of cystic fibrosis?
A 2-year-old with cystic fibrosis has failure to thrive, steatorrhea, and recurrent respiratory infections. Which test is the gold standard for confirming the diagnosis?
A 5-year-old with cystic fibrosis has a fecal elastase of 45 mcg/g. Which pancreatic enzyme replacement strategy is most appropriate?
Which of the following is the most sensitive imaging modality for detecting early chronic pancreatitis in children?
An infant with failure to thrive, steatorrhea, and acrodermatitis enteropathica-like rash is found to have low serum zinc. The diarrhea improves dramatically with zinc supplementation. Which condition should be suspected?
Which of the following is the most common cause of primary malabsorption in children in developing countries?
A 3-year-old with chronic diarrhea and fat-soluble vitamin deficiencies (low vitamins A, D, E, K) is found to have a normal sweat chloride test and normal small bowel biopsy. Which test would most likely confirm the diagnosis?
A child with Shwachman-Diamond syndrome presents with steatorrhea, neutropenia, and metaphyseal dysostosis. Which organ is primarily affected?
A 7-year-old boy presents with periumbilical pain that migrated to the right lower quadrant, anorexia, and low-grade fever. On examination, there is tenderness at McBurney's point and guarding. What is the most appropriate next step?
A 10-month-old infant presents with intermittent episodes of severe crying, drawing up of legs, and vomiting. Between episodes, the infant appears lethargic. On examination, a sausage-shaped mass is palpated in the right upper quadrant. What is the most likely diagnosis?
A child with suspected intussusception undergoes abdominal ultrasound. Which sonographic finding is diagnostic?
A 9-month-old with ileocolic intussusception is hemodynamically stable with no signs of peritonitis. What is the most appropriate initial treatment?
Which of the following is the most common pathological lead point for intussusception in children older than 2 years?
A 4-year-old presents with painless rectal bleeding. A technetium-99m pertechnetate scan shows uptake in the right lower quadrant. What is the most likely diagnosis?
Which of the following is the most common complication of Meckel diverticulum in children?
A child with acute appendicitis is found to have a perforated appendix with localized abscess on CT. The child is hemodynamically stable and afebrile. What is the most appropriate management?
Which of the following physical examination signs is most specific for retrocecal appendicitis?
A 3-year-old with intussusception undergoes successful air enema reduction. Which of the following is the most important post-reduction observation?
A 4-week-old infant presents with non-bilious projectile vomiting after every feed. On examination, a small mobile olive-shaped mass is palpated in the epigastrium. Laboratory tests show hypochloremic metabolic alkalosis. What is the diagnosis?
A newborn with severe respiratory distress has a scaphoid abdomen, and breath sounds are heard in the left hemithorax. The heart sounds are shifted to the right. What is the most likely diagnosis?
A 2-year-old with chronic constipation and painful defecation has a small tear in the posterior midline anal margin with a sentinel skin tag. What is the most appropriate management?
A newborn is noted to have a moist, pink, mucosal protrusion at the umbilicus with a small central opening. Fluid is seen leaking from the opening. What is the most appropriate management?
Which of the following is the most common type of tracheoesophageal fistula (TEF)?
A 7-year-old boy develops cola-colored urine, periorbital edema, and hypertension 2 weeks after recovering from streptococcal pharyngitis. Which organism is the most common cause of this condition?
In a child with suspected post-streptococcal glomerulonephritis following pharyngitis, when does the anti-streptolysin O (ASO) titer typically peak?
Which complement profile is most characteristic of acute post-streptococcal glomerulonephritis?
A 6-year-old girl with PSGN has moderate edema and a blood pressure at the 98th percentile. Which is the most appropriate initial management step?
A child with acute nephritic syndrome suddenly develops seizures, altered sensorium, and papilledema. Blood pressure is 170/110 mmHg. What is the most likely complication?
An 8-year-old boy presents with gross hematuria and mild flank pain that began 1 day after an upper respiratory tract infection. Serum C3 is normal. What is the most likely diagnosis?
A 10-year-old child presents with hematuria, proteinuria, edema, and rapidly rising creatinine over 2 weeks. Renal biopsy shows crescentic glomerulonephritis. What is the most appropriate next step in management?
Which statement correctly describes the typical latent period between streptococcal skin infection and the onset of post-streptococcal glomerulonephritis?
What is the long-term renal prognosis for children with typical post-streptococcal glomerulonephritis?
A child with acute nephritic syndrome is found to have RBC casts on urine microscopy. What does this finding most specifically indicate?
A 3-year-old boy presents with generalized edema and ascites. Urinalysis shows 4+ proteinuria and serum albumin is 1.8 g/dL. What is the most likely histopathological diagnosis?
A child with nephrotic syndrome is treated with prednisolone 2 mg/kg/day. By what time should complete remission (protein-free urine for 3 consecutive days) occur for the patient to be classified as steroid-sensitive?
A 4-year-old with nephrotic syndrome develops fever and abdominal pain. Ascitic fluid shows 500 cells/mm3 with 80% neutrophils. Gram stain is negative. What is the most likely organism causing spontaneous bacterial peritonitis?
A newborn presents with massive proteinuria, edema, and umbilical hernia within the first week of life. There is no response to corticosteroids. What is the most likely diagnosis?
A child with steroid-sensitive nephrotic syndrome has been in remission for 2 months. He now has 3+ proteinuria on dipstick for 4 consecutive days. How is this best classified?
A 5-year-old with minimal change disease has had 3 relapses in the past 8 months, all responding within 2 weeks of prednisolone. What classification best describes this pattern?
Renal biopsy in a child with steroid-sensitive nephrotic syndrome most commonly shows which histological finding?
A child with nephrotic syndrome presents with severe pallor, cold extremities, and a blood pressure of 70/40 mmHg. What is the most appropriate immediate intervention?
A child with nephrotic syndrome is started on furosemide for severe edema. Two days later, he develops abdominal pain and lethargy. Laboratory evaluation reveals a serum sodium of 128 mEq/L and potassium of 2.8 mEq/L. What is the most likely explanation?
An 8-year-old girl presents with nephrotic syndrome, arthritis, and a malar rash. She is found to have positive anti-dsDNA antibodies and low complement levels. What is the underlying cause of her nephrotic syndrome?
A 3-month-old infant with fever and irritability has a urine sample obtained by suprapubic aspiration. What colony count on culture is considered diagnostic of a urinary tract infection?
A 4-month-old boy is diagnosed with his first febrile urinary tract infection. According to standard guidelines, what is the most appropriate initial imaging sequence?
On micturating cystourethrogram, contrast is seen refluxing into a dilated ureter and pelvicalyceal system with blunting of the calyces but no ureteral tortuosity. What is the grade of vesicoureteral reflux?
A 3-year-old girl with Grade III vesicoureteral reflux and recurrent febrile UTIs is started on antibiotic prophylaxis. Which antibiotic is most commonly recommended for long-term prophylaxis?
A child had an acute febrile urinary tract infection 2 weeks ago. When is the optimal time to perform a DMSA scan to evaluate for renal cortical scarring?
Which of the following best defines recurrent urinary tract infection in a child?
A 2-year-old girl is diagnosed with Grade II vesicoureteral reflux after a febrile UTI. What is the most appropriate initial management?
Which virulence factor of uropathogenic Escherichia coli is most important for ascending infection and pyelonephritis?
A urine sample is collected from a 6-month-old girl using an adhesive bag for culture. The result shows mixed flora with 10,000 CFU/mL of E. coli. What is the most appropriate interpretation?
A newborn boy is noted to have a poor urinary stream and a palpable thick-walled bladder. Bilateral hydronephrosis is seen on antenatal ultrasound. What is the most likely diagnosis?
A 3-year-old child presents with pallor, oliguria, and bloody diarrhea after eating undercooked beef. Peripheral smear shows fragmented red blood cells. What is the classic triad of this condition?
Which serotype of Shiga toxin-producing Escherichia coli is most commonly associated with epidemic hemorrhagic colitis and typical HUS in children?
A child with HUS develops a serum potassium of 7.2 mEq/L, ECG showing peaked T waves, and persistent oliguria despite furosemide. What is the definitive management?
A 2-year-old develops HUS without preceding diarrhea. Laboratory studies show persistently low C3 and normal ADAMTS13 activity. Family history reveals a sibling who died of HUS. What is the most likely underlying mechanism?
A 9-year-old girl presents with fever, confusion, petechiae, and renal dysfunction. Laboratory studies show schistocytes and thrombocytopenia. Which additional feature completes the classic pentad of thrombotic thrombocytopenic purpura?
A child with septic shock develops bleeding from venipuncture sites, epistaxis, and oozing from a central line. Laboratory studies show prolonged PT and aPTT, low fibrinogen, and elevated D-dimer. What is the underlying pathophysiology?
A child presents with microangiopathic hemolytic anemia and thrombocytopenia. Which clinical feature most strongly favors thrombotic thrombocytopenic purpura over typical hemolytic uremic syndrome?
Which toxin produced by enterohemorrhagic Escherichia coli O157:H7 is primarily responsible for the endothelial damage seen in typical hemolytic uremic syndrome?
In a child with suspected HUS, which peripheral blood smear finding is most diagnostic?
A 7-year-old with TTP is admitted to the ICU. What is the treatment of choice to prevent irreversible neurologic and renal damage?
A 12-year-old with chronic kidney disease has an estimated GFR of 35 mL/min/1.73m2 for 3 months. What is the correct CKD stage?
Which of the following is an indication for initiating dialysis in a child with acute kidney injury?
In pediatric renal transplantation, what is the most common cause of long-term graft loss after the first post-transplant year?
Which form of renal replacement therapy is generally preferred as the initial modality for an infant with end-stage kidney disease awaiting transplantation?
A 6-year-old with CKD stage 4 has severe growth failure with a height below the 3rd percentile. Which therapy is most effective for improving long-term growth?
A child with chronic kidney disease develops bone pain, radiographic findings of subperiosteal resorption, and an elevated intact parathyroid hormone level. What is the primary underlying mechanism?
A 10-year-old with CKD stage 4 has a hemoglobin of 6.8 g/dL, normal iron studies, and a low serum erythropoietin level. What is the treatment of choice?
Which immunosuppressive agent is commonly used as part of the maintenance triple therapy regimen in pediatric renal transplantation?
A child with advanced CKD has a metabolic acidosis with a serum bicarbonate of 14 mEq/L. What is the primary mechanism?
A 14-year-old with suspected CKD stage 5 has small, echogenic kidneys on ultrasound. Which statement best explains why renal biopsy is generally contraindicated in this scenario?
A 4-year-old child presents with failure to thrive, polyuria, dehydration, and metabolic acidosis. Serum potassium is 2.8 mEq/L and urine pH is 7.2 despite acidemia. What is the most likely diagnosis?
A child with Fanconi syndrome has glycosuria, aminoaciduria, phosphaturia, and proximal renal tubular acidosis. What happens to the urine pH when the child develops severe systemic acidosis?
A child with obstructive uropathy and chronic kidney disease develops mild metabolic acidosis and a serum potassium of 6.2 mEq/L. Urine pH is 5.8. Which type of renal tubular acidosis is most likely?
A newborn with ambiguous genitalia presents with vomiting, dehydration, hyponatremia, and hyperkalemia. Serum 17-hydroxyprogesterone is markedly elevated. Which electrolyte pattern can this condition mimic?
Which combination of findings best distinguishes distal renal tubular acidosis (Type 1) from proximal renal tubular acidosis (Type 2)?
A 3-year-old child is found to have a large, smooth, non-tender abdominal mass that does not cross the midline. What is the most likely diagnosis?
A child with Wilms tumor undergoes nephrectomy. Pathology confirms tumor limited to the kidney, completely resected with intact capsule, and no vascular invasion. What is the stage according to the NWTS/COG system?
A newborn with aniridia is found to have genitourinary anomalies and later develops Wilms tumor. Which gene is most likely involved?
A 2-year-old with an abdominal mass is found to have elevated urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA). Which tumor is most likely?
At nephrectomy for Wilms tumor, the pathologist identifies persistent metanephric blastema in the surrounding renal parenchyma. What is the significance of this finding?
On physical examination, a left-sided abdominal mass in an infant is found to cross the midline and is associated with a hard, nodular texture. What is the most likely diagnosis?
A child with Wilms tumor undergoes staging evaluation. What is the most common site of metastasis?
According to the NWTS/COG staging system, a Wilms tumor that extends beyond the kidney but is completely resected without spillage is classified as which stage?
A 1-year-old boy presents with a large renal mass, hypercalcemia, and a concurrent brain tumor. Histology shows sheets of malignant rhabdoid cells. Which gene mutation is most likely?
A newborn is found to have a solid renal mass detected on antenatal ultrasound. Postnatally, the mass is well-circumscribed, does not invade surrounding tissue, and histology shows bundles of spindle cells resembling leiomyoma. What is the most likely diagnosis?
A 6-year-old child presents with cola-colored urine 2 weeks after a sore throat. Urine microscopy shows dysmorphic red blood cells and RBC casts. Where is the bleeding most likely originating?
Which statement about red blood cell morphology in urine is correct?
A 14-year-old adolescent has dipstick-positive proteinuria on a school health screening. A first-morning urine sample is negative for protein, but an afternoon sample is positive. What is the most likely diagnosis?
A 10-year-old boy has recurrent episodes of gross hematuria beginning 1-2 days after upper respiratory infections. Serum C3 is normal. Renal biopsy shows mesangial IgA deposition. What is the diagnosis?
An 8-year-old boy has persistent microscopic hematuria, sensorineural hearing loss, and a maternal uncle with end-stage renal disease. What is the most likely diagnosis?
A 12-year-old girl has persistent microscopic hematuria identified on routine screening. She is asymptomatic, has normal renal function, and no proteinuria. Her mother and maternal grandfather also had lifelong microscopic hematuria with normal kidney function. What is the most likely diagnosis?
A 7-year-old child is found to have asymptomatic microscopic hematuria on two separate occasions. What is the most appropriate next step in the diagnostic workup?
Which definition of persistent microscopic hematuria in children is most accurate?
A child with nephrotic-range proteinuria has a spot urine protein-to-creatinine ratio of 3.5 mg/mg. What does this value indicate?
A 16-year-old athlete develops transient gross hematuria after a marathon run. Urine microscopy shows isomorphic RBCs, and renal function is normal. The hematuria resolves completely after 48 hours of rest. What is the most likely cause?
A 6-year-old boy wets the bed every night but has no daytime urinary symptoms, no urgency, and no frequency. What is the most appropriate classification?
A 7-year-old with monosymptomatic nocturnal enuresis is started on desmopressin. What is the mechanism of action of this medication?
Which statement about enuresis alarm therapy is most accurate?
A 5-year-old girl has nocturnal enuresis accompanied by daytime urgency, frequency, and occasional daytime wetting. She also has chronic constipation. What classification best fits this presentation?
A 7-year-old girl has recurrent urinary tract infections and a staccato, interrupted urinary stream. Uroflowmetry shows peaks and plateaus. She does not have neurologic disease. What is the most likely diagnosis?
A 6-year-old with urgency and daytime incontinence is started on oxybutynin. What is the primary mechanism of action of this medication?
According to ICCS and standard pediatric guidelines, at what age is nocturnal enuresis typically diagnosed?
A 6-year-old girl has daytime urinary incontinence with urgency and frequency but no nocturnal enuresis. She has no neurologic abnormalities. What is the most likely underlying cause?
An 8-year-old girl experiences complete bladder emptying whenever she laughs hard during play. She has no other urinary symptoms and normal voiding patterns. What is this phenomenon called?
A 5-year-old boy has daytime urinary frequency (every 30 minutes), small voided volumes, and occasional urgency incontinence. He has no nocturia or nocturnal enuresis. Urinalysis and culture are normal. What is the most likely diagnosis?
A 3-week-old newborn screened at a hospital in Kerala has a filter-paper TSH of 45 mIU/L (cutoff >20). The infant appears normal on examination. What is the most appropriate next step?
An 8-year-old girl is brought with fatigue, constipation, weight gain, and poor school performance. Examination reveals a firm, non-tender goiter. Her height is at the 10th percentile (down from 50th at age 5). Which autoantibody pair is most specific for the likely diagnosis?
A 7-day-old infant with confirmed congenital hypothyroidism (TSH 280 mIU/L, free T4 0.4 ng/dL) is started on levothyroxine. What is the recommended starting dose and target for normalization of T4?
A 6-year-old boy presents with short stature. His bone age is delayed by 3 years. Growth hormone stimulation testing is normal, but TSH is 18 mIU/L and free T4 is 0.6 ng/dL. What is the most likely explanation for his growth failure?
A 2-week-old infant is diagnosed with congenital hypothyroidism. Which of the following is the most common underlying etiology?
A 10-year-old girl with untreated Hashimoto thyroiditis is noted to have galactorrhea. Pelvic ultrasound shows multicystic ovaries. Which mechanism best explains these findings?
During a medical camp in a hilly district of Kerala, you encounter a 4-year-old child with coarse facial features, a large protuberant tongue, umbilical hernia, and delayed developmental milestones. The child did not undergo newborn screening. What is the most likely permanent neurologic consequence if treatment is delayed beyond 3 months of age?
A 14-year-old girl with Hashimoto thyroiditis on stable levothyroxine presents with palpitations, tremors, and insomnia. Her TSH is 0.1 mIU/L and free T4 is 2.1 ng/dL. Which is the most likely cause?
A newborn with Down syndrome is being monitored closely. At 4 weeks, the TSH is 25 mIU/L and free T4 is 0.9 ng/dL. What is the recommended management?
Which of the following laboratory findings best distinguishes primary hypothyroidism from secondary (pituitary) hypothyroidism?
A 15-year-old girl presents with 3 months of weight loss, heat intolerance, palpitations, and tremor. Examination reveals a diffuse goiter, exophthalmos, and resting tachycardia (120 bpm). Which test is most specific for confirming the underlying autoimmune etiology?
A 14-year-old with newly diagnosed Graves disease has mild disease without ophthalmopathy. What is the recommended first-line treatment?
A 16-year-old girl on methimazole for Graves disease develops jaundice and right upper quadrant pain. Liver enzymes show AST 450 U/L and ALT 520 U/L. Which antithyroid drug is most commonly associated with this complication, and what is the appropriate management?
A mother with active Graves disease gives birth to a full-term infant. At 48 hours, the infant is irritable, tachycardic (180 bpm), has a small goiter, and is feeding poorly. What is the pathophysiology of this condition?
A 12-year-old with Graves disease develops high fever (40°C), severe tachycardia, agitation, and vomiting 2 days after stopping methimazole due to a viral illness. What is the most appropriate immediate pharmacologic intervention?
A 9-year-old boy presents with a solitary thyroid nodule and biochemical hyperthyroidism. There is no family history of thyroid disease. What is the most appropriate next step in management?
An adolescent with Graves disease on methimazole asks about the chance of permanent remission if antithyroid drugs are continued for 2 years. What is the approximate remission rate in children?
A 5-year-old boy is referred for evaluation of short stature. His height is 95 cm (<3rd percentile), and he has grown only 3 cm in the past year. His birth weight was 3.2 kg at term. His parents' heights are at the 50th percentile. What is the most appropriate initial screening test?
A 6-year-old boy with confirmed GH deficiency starts recombinant human GH therapy at 0.3 mg/kg/week. What is the expected growth velocity in the first year of treatment?
A 13-year-old boy is short (height 3rd percentile) but has grown consistently along his growth curve. His bone age is 11 years. His father had his growth spurt at age 15. The boy has no dysmorphic features and normal IGF-1/IGFBP-3. What is the most likely diagnosis?
A 4-year-old girl born small for gestational age (birth weight 1.8 kg at term) has not shown catch-up growth. Her current height is -2.8 SD. She is otherwise healthy with normal development. Which treatment is indicated?
A 12-year-old girl with short stature, webbed neck, low posterior hairline, and broad chest with widely spaced nipples is evaluated. Which karyotype finding and GH therapy indication are most likely?
A 7-year-old boy on GH therapy for 18 months complains of progressive right hip and knee pain and begins to limp. Examination reveals limited internal rotation of the right hip. What is the most likely complication?
In interpreting a growth chart, a child whose height percentile has dropped from the 50th to the 10th over 2 years is most concerning for which of the following?
A 9-year-old boy with craniopharyngioma resection 6 months ago now presents with polyuria (5 L/day), polydipsia, and nocturia. Serum sodium is 148 mEq/L, urine specific gravity is 1.002. What is the most likely diagnosis?
A child with central diabetes insipidus undergoes a water deprivation test. After 4 hours, urine osmolality remains <300 mOsm/kg while serum osmolality rises to 305 mOsm/kg. After DDAVP administration, urine osmolality increases to 650 mOsm/kg. What does this confirm?
A 6-year-old girl is brought to clinic because her mother noticed breast budding. On examination, there is Tanner stage 2 breast development, but no pubic hair. Bone age is advanced by 2 years. Which test best distinguishes true central precocious puberty from peripheral causes?
A 5-year-old girl has rapidly progressive breast development, vaginal bleeding, and acne over 3 months. Bone age is advanced by 4 years. GnRH stimulation test shows prepubertal LH response. What is the most likely underlying mechanism?
A 7-year-old girl with confirmed central precocious puberty has a bone age of 10 years and predicted adult height of 145 cm. What is the treatment of choice to preserve adult height?
A 15-year-old boy has no testicular enlargement (testicular volume <4 mL), sparse pubic hair, and a height at the 3rd percentile. His father and paternal uncle had their growth spurts at age 16. Bone age is 12 years. What is the most likely diagnosis?
A 14-year-old boy with delayed puberty has no sense of smell (anosmia) and color blindness. His testicular volume is 3 mL, and serum testosterone is 50 ng/dL. MRI shows absent olfactory bulbs. What is the diagnosis?
A 4-year-old girl has irregular café-au-lait spots with irregular ('coast of Maine') borders, precocious puberty with vaginal bleeding, and fibrous dysplasia of the right femur on X-ray. Which genetic mutation is most likely responsible?
An 11-year-old girl with central precocious puberty is treated with a GnRH analog. Which expected outcome best indicates successful therapy?
In a 14-year-old boy, which finding represents the first reliable sign of pubertal onset?
A 16-year-old girl with primary amenorrhea has a height of 142 cm, webbed neck, low posterior hairline, and widely spaced nipples. Her FSH is 85 mIU/L and estradiol is <10 pg/mL. Which karyotype and associated endocrine condition are most likely?
An 8-year-old boy with known type 1 diabetes mellitus presents with 2 days of vomiting, abdominal pain, and rapid breathing. His blood glucose is 480 mg/dL, pH is 7.12, bicarbonate is 8 mEq/L, and ketones are large in urine. How is the severity of his diabetic ketoacidosis (DKA) classified?
A 6-year-old child presents in severe DKA with signs of hypovolemic shock (tachycardia, poor perfusion, hypotension). What is the most appropriate initial fluid management?
A 10-year-old in DKA has received 2 hours of fluid resuscitation. Blood glucose is 420 mg/dL. When should intravenous insulin infusion be started, and at what dose?
A child with DKA has a serum potassium of 3.2 mEq/L after 2 hours of fluid resuscitation. Urine output is adequate. What is the correct management?
A 7-year-old with DKA, after 4 hours of treatment, develops a severe headache, bradycardia (heart rate 60), hypertension (150/100), and altered mental status. What is the most appropriate immediate intervention?
A 9-year-old newly diagnosed with type 1 DM is started on basal-bolus insulin. After 3 weeks, his insulin requirement drops from 0.8 U/kg/day to 0.2 U/kg/day while maintaining normal glucose. What phenomenon explains this?
A 12-year-old with T1DM develops gastroenteritis with vomiting and is unable to eat solid food. Her blood glucose is 220 mg/dL, and urine ketones are moderate. What is the most appropriate sick-day management?
A 15-year-old with T1DM on insulin glargine and lispro has persistent fasting hyperglycemia (180-220 mg/dL) despite normal pre-dinner glucose. His mother checks his 2 AM glucose, which is 60 mg/dL. What is the most likely explanation?
Which autoantibody panel is most specific for confirming the autoimmune etiology of type 1 diabetes mellitus in a newly diagnosed child?
According to ADA guidelines, what is the recommended glycemic target (HbA1c) for most children and adolescents with type 1 diabetes mellitus?
A 13-year-old obese boy (BMI >95th percentile) with a family history of type 2 DM is asymptomatic. When should screening for type 2 diabetes begin, and which test is preferred?
A 16-year-old obese adolescent is newly diagnosed with diabetes. He has acanthosis nigricans, no ketones in urine, detectable C-peptide, and negative T1DM autoantibodies. What is the most likely diagnosis?
A 14-year-old obese girl is diagnosed with type 2 diabetes mellitus. Her HbA1c is 8.2% and she has no ketonuria. What is the recommended initial pharmacologic therapy?
A 12-year-old obese boy has a dark, velvety hyperpigmented patch on the posterior neck and axillae. His fasting insulin is 35 μU/mL (elevated). What is the clinical significance of this skin finding?
A 15-year-old obese girl with irregular menses, acne, and hirsutism is evaluated. Ultrasound shows enlarged ovaries with multiple small follicles. Which endocrine disorder is most likely, and what is the first-line intervention?
Which of the following best defines metabolic syndrome in children and adolescents?
A 10-year-old obese child is found to have elevated alanine aminotransferase (ALT 85 U/L) on routine screening. He denies alcohol use, viral hepatitis serologies are negative, and ultrasound shows increased hepatic echogenicity. What is the most likely diagnosis?
A newborn female infant has ambiguous genitalia (enlarged clitoris, fused labioscrotal folds). At day 10 of life, she develops vomiting, dehydration, hyponatremia (125 mEq/L), and hyperkalemia (6.8 mEq/L). What is the most likely enzymatic defect?
Newborn screening for congenital adrenal hyperplasia (CAH) is performed by measuring which metabolite on a filter-paper blood spot?
An infant with classic salt-wasting congenital adrenal hyperplasia is being started on maintenance therapy. Which medications are required for optimal treatment?
A 3-year-old with known salt-wasting CAH presents with vomiting, lethargy, and shock after an episode of gastroenteritis. What is the most appropriate immediate management?
A 5-year-old girl is being evaluated for precocious puberty. She has clitoromegaly, pubic hair, and advanced bone age, but no history of salt-wasting crises and normal electrolytes. Which form of CAH is most likely?
A 12-year-old boy presents with increasing pigmentation of skin creases, gums, and scars. He has postural dizziness, hypotension, and hyponatremia (130 mEq/L) with hyperkalemia (5.9 mEq/L). What is the most specific confirmatory test?
A child who has been on chronic high-dose prednisone for nephrotic syndrome has the dose tapered rapidly and stopped. Two days later, he presents with fatigue, abdominal pain, and hypotension. Laboratory studies show sodium 132 mEq/L and potassium 4.0 mEq/L. What is the most likely diagnosis?
An adolescent with episodic severe headaches, palpitations, sweating, and hypertension (180/110 during episodes) is evaluated. A 24-hour urine collection shows elevated metanephrines and normetanephrines. What is the most likely diagnosis?
A child with primary hyperaldosteronism is evaluated. Which set of laboratory findings is most consistent with this diagnosis?
A newborn boy has a midline cleft lip and palate, micropenis, and hypoglycemia on day 2 of life. His cortisol is 2 mcg/dL and GH is <0.1 ng/mL. Which congenital syndrome should be suspected, and what is the first hormone to replace?
A 10-year-old child with septo-optic dysplasia is being monitored. Which associated endocrine deficiency is most likely to be present?
A child with central diabetes insipidus is started on DDAVP (desmopressin). Which statement about DDAVP therapy is most accurate?
A 5-year-old post-operative neurosurgery patient develops hyponatremia (Na 128 mEq/L). He is euvolemic with normal skin turgor. Urine sodium is 45 mEq/L and urine osmolality is 650 mOsm/kg. What is the most likely diagnosis?
A child with SIADH has a serum sodium of 125 mEq/L and is asymptomatic. What is the most appropriate initial management?
A child with central diabetes insipidus is treated with DDAVP. The mother reports that the child sometimes becomes confused and lethargic in the late afternoon. Which complication of DDAVP therapy should be suspected?
After transsphenoidal surgery for craniopharyngioma, a child initially has polyuria, then develops hyponatremia 5 days post-op, followed by recurrent polyuria 10 days later. What is this classic pattern called?
A newborn with hypoglycemia is found to have low cortisol, low T4, low testosterone, and low GH. MRI shows an ectopic posterior pituitary bright spot and absent pituitary stalk. Which transcription factor mutation is most commonly associated with this phenotype?
Which of the following is the most sensitive initial screening test for growth hormone deficiency in a child with short stature?
An 18-month-old toddler is brought with bowing of the legs and a prominent anterior chest wall. Examination reveals widening of the wrists and ankles. X-ray of the wrist shows cupping and fraying of the metaphyses. Which is the most likely diagnosis?
A 10-month-old infant with nutritional rickets is started on treatment. Which regimen is most appropriate for achieving rapid healing?
A 3-year-old child has short stature, bowed legs, and delayed walking. Laboratory studies show serum calcium 9.2 mg/dL (normal), phosphate 2.1 mg/dL (low), alkaline phosphatase 1200 U/L (elevated), PTH 45 pg/mL (normal), and 25-OH vitamin D 28 ng/mL (normal). What is the most likely diagnosis?
A child with chronic kidney disease stage 4 develops bone pain and deformities. Laboratory studies show calcium 8.5 mg/dL, phosphate 6.2 mg/dL, PTH 450 pg/mL, and 25-OH vitamin D 18 ng/mL. What is the primary pathophysiologic mechanism of renal osteodystrophy?
A 2-year-old with rickets has low calcium (8.0 mg/dL), elevated PTH (180 pg/mL), low phosphate (2.5 mg/dL), normal 25-OH vitamin D, and low 1,25-(OH)2 vitamin D. Which enzyme deficiency is most likely responsible?
An exclusively breastfed 6-month-old infant presents with hypocalcemic seizures. Serum calcium is 6.8 mg/dL, phosphate is 8.5 mg/dL, and PTH is undetectable. The mother has a history of thyroid surgery. Which diagnosis is most likely?
A 3-day-old infant born at term develops jitteriness and seizures. Serum calcium is 6.5 mg/dL, phosphate is 5.8 mg/dL, and PTH is 5 pg/mL (low-normal). The infant's mother has well-controlled gestational diabetes. What is the most likely cause of hypocalcemia?
An infant is diagnosed with DiGeorge syndrome (22q11.2 deletion). Which classic triad of findings is most characteristic?
A 3-month-old infant with failure to thrive is found to have serum calcium 12.5 mg/dL, phosphate 2.8 mg/dL, and PTH 8 pg/mL (low). The infant has a characteristic 'elfin facies,' supravalvular aortic stenosis murmur, and friendly personality. What is the most likely diagnosis?
A 12-year-old girl has short stature, obesity, round face, shortened 4th and 5th metacarpals, and subcutaneous calcifications. Her calcium is 7.2 mg/dL, phosphate is 5.8 mg/dL, and PTH is 185 pg/mL (elevated). What is the most likely diagnosis?