Clinical features

The most important feature in diagnosis is a high index of suspicion. Clinical features are as follows:

• most commonly occurs following diarrhoeal illness
• blood passed in the stool of any child with diarrhoea should alert to the diagnosis
• there may be a mild amount of dehydration; however this is out of proportion to the degree of uraemia found in the blood
• renal abnormalities - oliguria is common although in some cases the patient may be polyuric with proteinuria and haematuria
• cardiovascular abnormalities:
  • if HUS is diarrhoea-associated then the patient is generally normotensive (1)
  • severe hypertension and retinopathy are associated with sporadic cases of HUS
• CNS abnormalities - such as irritability, restlessness, drowsiness, cerebellar ataxia and coma may occur, more commonly in females
• skin purpura - more common in TTP
• gastrointestinal abnormalities - as well as there often being an acute diarrhoeal illness, HUS may present with perforation or infarction if the microvascular disease involves the bowel itself
• rhabdomyolysis has been reported

Reference:

• (1) Neild GH (1993). Haemolytic uraemic syndrome in practice. Lancet, 343, 398-402