What are the key clinical features to consider when diagnosing Haemolytic Uraemic Syndrome (HUS) in children?

Key clinical features to consider when diagnosing haemolytic uraemic syndrome (HUS) in children include:

• Microangiopathic hemolytic anemia evidenced by pallor, fatigue, and laboratory findings of anemia with schistocytes on blood film.
• Thrombocytopenia presenting as bruising, petechiae, or bleeding tendencies due to low platelet counts.
• Acute kidney injury manifesting as reduced urine output, oedema, hypertension, and elevated serum creatinine.
• Prodromal diarrhoeal illness, often bloody, typically caused by Shiga toxin-producing Escherichia coli (STEC), preceding the onset of HUS symptoms.
• Other systemic features such as hypertension, neurological symptoms (e.g., irritability, seizures), and gastrointestinal symptoms may also be present.

These features reflect the triad of HUS: hemolytic anemia, thrombocytopenia, and acute kidney injury, which is critical for diagnosis in children NICE CG84 Donadelli et al. 2023. Atypical HUS, which may be associated with genetic variants such as DGKE mutations, can present similarly but often lacks the diarrhoeal prodrome and may have a more insidious onset Dai et al. 2023. Therefore, clinical suspicion should be high in children presenting with this triad, especially following a diarrhoeal illness, but also in those with unexplained hemolysis and renal impairment without diarrhoea NICE CG84 Dai et al. 2023Donadelli et al. 2023.