Hemophagocytic Lymphohistiocytosis Complicating a Case of Drug‐Induced Liver Injury Precipitated by Cephalexin: A Rare Consequence of Commonly Prescribed Medications

Drug-induced liver injury (DILI) is a relatively rare clinical syndrome that accounts for a significant proportion of acute liver failure progressing to transplant in the United States. Some drugs such as acetaminophen are classically associated with a predictable pattern of DILI that can often be reversed with prompt administration of guideline-directed therapeutics. In other cases, commonly prescribed medications can lead to an unpredictable variant of DILI in certain vulnerable populations for which few guidelines on management exist, likely in part due to the heterogeneity of precipitating toxins. We report a case of idiosyncratic DILI caused by cephalexin that progressed to fulminant hemophagocytic lymphohistiocytosis (HLH) in a young and previously healthy patient, alongside our experiences with therapeutic management and outcomes guided by a multidisciplinary team.