A patient presents with one day of right upper quadrant pain after fatty meals, along with nausea, altered mental status, jaundice, and fever. What is the most likely diagnosis?

• A. Acute pancreatitis
• B. Acute cholecystitis
• C. Acute cholangitis
• D. Hepatic abscess

Answer: (C)

Fever with right upper quadrant pain and jaundice points to infection of the biliary system with obstruction, i.e., acute cholangitis. The trio of RUQ pain, fever, and jaundice is classic (Charcot’s triad) and reflects a blocked biliary tract that becomes secondarily infected. The altered mental status adds Reynolds pentad, indicating systemic infection and possible sepsis, which can occur with cholangitis if not treated promptly.

Fatty meals hint at gallstone disease, which can lodge in the common bile duct and cause biliary obstruction leading to infection.

Acute pancreatitis typically presents with epigastric pain that can radiate to the back and elevated pancreatic enzymes, not the combination of RUQ pain with jaundice and systemic infection described here. Acute cholecystitis causes RUQ pain and fever and leukocytosis, but jaundice is not a defining feature unless there’s CBD involvement. A hepatic abscess can present with fever and RUQ pain but doesn’t characteristically produce the same jaundice plus sepsis picture as cholangitis.

Therefore, the presentation best fits acute cholangitis.