Adult Shigatoxin-mediated hemolytic uremic syndrome masked by alcohol use and inflammatory bowel disease.

Diagnosing uncommon diseases in individuals with underlying medical conditions can be challenging. Cognitive bias can lead to delayed or missed disease management. We present a case of Shiga-toxin mediated hemolytic uremic syndrome (ST-HUS) in a 46-year-old man with ulcerative colitis and alcohol use disorder who presented with acute alcohol intoxication, non-bloody diarrhoea and coffee ground emesis. He was admitted to the hospital for alcoholic ketoacidosis, alcohol withdrawal and possible upper gastrointestinal bleed, but ultimately, he developed severe thrombocytopaenia, hemolytic anaemia, acute renal failure and prolonged altered mentation. Given that ST-HUS is uncommon in adults, his initial report of diarrhoea was attributed to alcohol use or underlying active ulcerative colitis and not connected to his haematologic abnormalities. He was initially started on plasmapheresis; however, thrombotic microangiopathy work up revealed Shiga-toxin in his stool and ADAMST13 levels within normal limits. Subsequently, he was transitioned to supportive care for management of ST-HUS.