Haemolytic uraemic syndrome (HUS) occurs when there is thrombosis within small blood vessels throughout the body. This is usually triggered by a bacterial toxin called shiga toxin. It leads to the classic triad of:
- Haemolytic anaemia: anaemia caused by red blood cells being destroyed
- Acute kidney injury: failure of the kidneys to excrete waste products such as urea
- Thrombocytopenia: low platelet count
The most common cause is a toxin produced by the e. coli 0157 bacteria, called the shiga toxin. Shigella also produces this toxin. The use of antibiotics and anti-motility medications such as loperamide to treat gastroenteritis caused by these pathogens increases the risk of developing HUS.
E. coli 0157 causes a brief gastroenteritis, often with bloody diarrhoea. The symptoms of haemolytic uraemic syndrome typically start around 5 days after the onset of the diarrhoea.
Signs and symptoms of HUS may include:
- Reduced urine output
- Haematuria or dark brown urine
- Abdominal pain
- Lethargy and irritability
HUS is a medical emergency and has a 10% mortality. It needs to be managed by experienced paediatricians under the guidance of a renal specialist. The condition is self limiting and supportive management is the mainstay of treatment:
- Urgent referral to the paediatric renal unit for renal dialysis if required
- Antihypertensives if required
- Careful maintenance of fluid balance
- Blood transfusions if required
70 to 80% of patients make a full recovery.
Last updated August 2019