Drug Reaction With Eosinophilia and Systemic Symptoms and Severe Drug-Induced Liver Injury After Off-Label Zonisamide Use for Weight Loss.

Drug-related eosinophilia with systemic symptoms (DRESS) is a drug-induced hypersensitivity reaction causing rash and systemic symptoms. Associated liver injury ranges from abnormal laboratory results to liver failure. We report a case of zonisamide-induced DRESS with severe liver injury, characterized by vanishing bile duct syndrome. Despite stopping zonisamide and initiating immunosuppressive therapy, the patient's hepatic function remained abnormal. After a prolonged course, the patient died from pneumonia and Hodgkin lymphoma. This case highlights the gravity of DRESS syndrome and drug-induced liver injury along with the risks of immunosuppressive therapies.