Snapshot A 4-year-old girl is admitted to the floor with a several day history of bloody diarrhea. Other members of the daycare she attends also had bloody diarrhea. She is irritable and lethargic. Her skin has also turned slightly yellow. Her arms have multiple petechiae. Lab results show creatinine of 4.0 mg/dL, platelet of 40,000/mm3, and hemoglobin of 7 g/dL. A peripheral blood smear shows schistocytes. Introduction Syndrome commonly seen in children most commonly caused by Escherichia coli O157:H7 (EHEC) acute diarrhea due to Shiga-like toxin cytokine release, causing HUS does not invade GI mucosa Shigella spp. Shiga toxin cytokine release, causing HUS GI mucosal damage S. pneumoniae infection Classic triad thrombocytopenia (first) nonimmune microangiopathic hemolytic anemia (second) acute renal failure (hence, “uremia” in title) (third) Similar to TTP but without fever and neurologic symptoms Pathogenesis toxin causes cytokine release → damages endothelium microthrombi form at site of damage consumes platelets → thrombocytopenia intravascular mechanical hemolysis → schistocytes decreases renal blood flow → acute renal failure Epidemiology most commonly in children exposed to E. coli raw or undercooked meat unwashed fruits/vegetables animals at petting zoo Presentation Symptoms prodromal gastrointestinal illness abdominal pain bloody diarrhea nausea vomiting fatigue (anemia) Physical exam pallor (anemia) jaundice (hemolysis) Evaluation Complete blood count anemia thrombocytopenia Peripheral smear schistocytes (helmet cells) ↑ serum creatinine ↑ bleeding time Normal PT/PTT Differential Diagnosis Sepsis TTP DIC Treatment Supportive care with fluids to maintain renal perfusion Prognosis, Prevention, and Complications Prognosis 3-5% mortality 5% severe sequelae such as end-stage renal failure Prevention prevent EHEC infection avoid raw or undercooked meat Complications chronic kidney disease electrolyte abnormalities