A 17-year-old female presents with fatigue, malaise, and jaundice. Her laboratory results show markedly elevated aminotransferases (> 1,000 IU/L) and a polyclonal hypergammaglobulinemia, raising suspicion for autoimmune hepatitis. Which pattern of autoantibodies is most characteristic of type 1 autoimmune hepatitis?
An 8-year-old girl is diagnosed with cyclic vomiting syndrome (CVS) and has a strong family history of migraines. During an acute episode, she is brought to the emergency department with intractable vomiting. Which abortive medication is specifically noted to be useful in patients with this migraine-related subgroup of CVS?
A 14-year-old black adolescent presents for a routine check-up. A dental examination reveals significant, rapid alveolar bone loss localized to at least two first molars and incisors, but the rest of her dentition is healthy. Which of the following is the most likely underlying pathophysiologic feature of this condition?
A 6-week-old female infant is evaluated for persistent jaundice and has had acholic stools for the past two weeks. An abdominal ultrasound demonstrates a small, contracted gallbladder and a triangular cord sign. Biliary atresia is suspected. What is the gold standard for establishing a definitive diagnosis?
A 17-year-old female with a 5-year history of ulcerative pancolitis is in remission on mesalamine. She asks about her long-term cancer risk. When should she begin surveillance colonoscopies to screen for dysplasia?
A 7-year-old child with no significant past medical history presents with an episode of hematemesis. On examination, his liver is not palpable, but he has significant splenomegaly. His mother recalls that as a neonate, he was hospitalized for a severe umbilical cord infection (omphalitis) that required umbilical vein catheterization. What is the most likely cause of this child’s portal hypertension?
A 1-year-old infant with chronic diarrhea undergoes evaluation. Stool analysis reveals a pH of 5.0 and is positive for reducing substances. A breath hydrogen test is ordered. What finding on the breath hydrogen test would be considered positive in the most likely diagnosis?
A 7-year-old boy with extrahepatic portal venous obstruction (EHPVO) undergoes a screening upper endoscopy. The procedure reveals large esophageal varices with red marks, but he has never had a bleeding episode. When discussing primary prophylaxis to prevent a first variceal bleed, which of the following interventions has supporting evidence for its use in this specific pediatric population?
A 10-year-old boy with a family history of pancreatitis in successive generations presents with his third episode of acute pancreatitis. Genetic testing is pursued and identifies a pathogenic variant in the cationic trypsinogen (PRSS1) gene. What is the underlying pathophysiologic mechanism of pancreatitis in this patient?
A pediatric resident is explaining normal nutrient absorption to a medical student. They correctly state that iron is primarily absorbed in which segment of the small intestine?
