Hemolytic Uremic Syndrome in Emergency Medicine Clinical Presentation

Updated: Jun 24, 2021
  • Author: Audrey J Tan, DO; Chief Editor: Steven C Dronen, MD, FAAEM  more...
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The presentation in patients with hemolytic uremic syndrome (HUS) may vary with the etiology. Typical HUS (ie, Shiga toxin–related) presents as follows:

  • Recent history may include such risk factors as eating rare hamburger, a trip to a petting zoo, or contact with persons with diarrhea
  • Diarrhea, which becomes hemorrhagic in 70% of cases, usually within 1-2 days
  • Vomiting, in 30-60% of cases
  • Fever, in 5-20% of cases
  • After 4-6 days, sudden onset of the clinical manifestations of HUS: pallor and shortness of breath from hemolytic anemia, and reduced or absent urine output due to acute kidney injury
  • Neurologic symptoms in 33% of patients (eg, irritability, seizures, or altered mental status)
  • Diarrhea may improve as the other HUS signs and symptoms begin 

Atypical HUS does not typically begin with a gastrointestinal (GI) illness. Patients with pneumococcal HUS may have had a recent respiratory illness. Clinical manifestations of atypical HUS are similar to those of typical HUS, although neurologic involvement is more common.


Physical Examination

Findings in patients with hemolytic uremic syndrome reflect those of the inciting prodromal illness and the end organ in which thrombogenesis is occurring, as follows:

  • Gastrointestinal: GI bleeding is often noted. GI involvement may lead to symptoms of an acute abdomen, with occasional peritonitis.
  • Cardiac involvement may lead to congestive heart failure (CHF) and arrhythmias.
  • Microinfarcts in the pancreas may cause pancreatitis or rarely, insulin-dependent diabetes mellitus.
  • Ocular involvement may lead to retinal or vitreous hemorrhages.
  • Hypertension and oliguria are typical findings consistent with renal compromise.