Helicobacter pylori Eradication Therapy–Associated Drug-Induced Liver Injury in a Patient With Primary Biliary Cholangitis

Drug-induced liver injury (DILI) is a rare but serious complication of <i>Helicobacter pylori</i> eradication therapy, especially in patients with pre-existing liver disease. We report a 75-year-old man with well-controlled primary biliary cholangitis (PBC) who developed jaundice and pruritus after treatment with vonoprazan, amoxicillin, and clarithromycin. Liver biopsy showed an enlarged portal area, enlarged hepatocytes around the central vein, eosinophil infiltration, and focal necrosis, but PBC deterioration was ruled out. A positive drug lymphocyte stimulation test confirmed DILI. This case highlights the importance of liver biopsy and drug lymphocyte stimulation test in differentiating DILI from PBC exacerbation.