From the Guidelines
Hemolytic Uremic Syndrome (HUS) typically presents with a triad of symptoms: acute kidney injury, microangiopathic hemolytic anemia, and thrombocytopenia, often preceded by gastrointestinal symptoms such as bloody diarrhea, abdominal pain, and vomiting, as noted in the 2017 Infectious Diseases Society of America clinical practice guidelines 1. The symptoms of HUS can be divided into several categories, including:
- Gastrointestinal symptoms:
- Bloody diarrhea
- Abdominal pain
- Vomiting
- Sometimes fever, particularly in the more common form that follows an infection with Shiga toxin-producing E. coli, as highlighted in the study 1
- Symptoms related to kidney damage:
- Decreased urine output
- Pallor
- Fatigue
- Symptoms related to thrombocytopenia and hemolysis:
- Bruising or unusual bleeding
- Jaundice
- Other symptoms:
- High blood pressure
- Neurological symptoms such as irritability, seizures, or altered consciousness in severe cases
- Edema or fluid overload as kidney function deteriorates It is essential to note that approximately 10% of patients with HUS do not have bloody diarrhea 1, and the absence of fever at first medical evaluation can be associated with an increased risk of STEC O157 infection 1. The early identification of STEC infections, particularly those carrying Shiga toxin 2 (stx2) genes, is crucial to reduce the risk of complications, including HUS, as these strains are associated with increased risk of both bloody diarrhea and HUS 1.
From the Research
Symptoms of Hemolytic Uremic Syndrome (HUS)
The symptoms of Hemolytic Uremic Syndrome (HUS) include:
- Hemolytic anemia with schistocytes 2
- Thrombocytopenia without evidence of disseminated intravascular coagulation 2
- Renal failure 2
- Hypertension and acute renal failure (ARF) 2
- Organ impairment 3
- Microangiopathic hemolytic anemia, thrombocytopenia, and hyperazotemia 4
- Jaundice and petechiae 4
- Pulmonary hemorrhage and gastrointestinal bleeding (in some cases) 4
- Restlessness, severe hypertension, anemia, respiratory distress, and acute kidney injury (in some cases) 5
Atypical HUS Symptoms
Atypical HUS (aHUS) may also present with:
- No prodromal diarrhea 2, 6
- Sporadic or familial occurrence 2, 6
- Overactivation of the complement alternate pathway 2, 6
- Mutation in one or more genes coding for proteins involved in regulation or activation of the alternative pathway of complement 6
- Central nervous system involvement (in some cases) 4
Extrarenal Manifestations
Extrarenal manifestations of aHUS can include: