A 28-year-old woman presents with worsening fatigue, generalized pruritus, and jaundice. Her medical history is unremarkable. Physical exam reveals scleral icterus and excoriations on her arms. Laboratory tests show elevated total bilirubin, predominantly direct, significantly elevated alkaline phosphatase, and mildly elevated AST/ALT. Antimitochondrial antibodies (AMAs) are positive. What is the most likely diagnosis?

The correct answer to the question "A 28-year-old woman presents with worsening fatigue, generalized pruritus, and jaundice. Her medical history is unremarkable. Physical exam reveals scleral icterus and excoriations on her arms. Laboratory tests show elevated total bilirubin, predominantly direct, significantly elevated alkaline phosphatase, and mildly elevated AST/ALT. Antimitochondrial antibodies (AMAs) are positive. What is the most likely diagnosis?" is Option C: Primary biliary cholangitis.

The other options — A) Acute viral hepatitis, B) Choledocholithiasis, D) Hemochromatosis — are incorrect for this USMLE Exam Prep question. As explained above: This presentation with pruritus, jaundice, elevated alkaline phosphatase, and positive antimitochondrial antibodies is highly characteristic of primary biliary cholangitis (PBC). PBC is an autoimmune…