Emergency Medicine In-Training Examination (EM-ITE) Practice Test

Hemolytic uremic syndrome (HUS) is most commonly seen in children, often following an episode of diarrhea due to infection, particularly with Shiga toxin-producing Escherichia coli (STEC), such as E. coli O157:H7. The classical triad of symptoms in HUS includes hemolytic anemia, acute renal failure, and thrombocytopenia.

In this context, bloody diarrhea is a salient feature due to the initial gastrointestinal infection leading to the syndrome. As the condition progresses, affected children may experience vomiting due to gastrointestinal distress, and renal failure becomes apparent as the kidneys begin to fail, resulting in a decreased ability to filter waste and maintain fluid balance.

The presence of bloody diarrhea and vomiting is indicative of the gastrointestinal prodrome often preceding HUS, while renal failure manifests through decreased urine output, elevated creatinine levels, and potentially fluid overload. These symptoms are hallmark presentations, making this option the most typical clinical presentation for children with hemolytic uremic syndrome.