A 8-year-old boy presents with petechiae, azotemic oliguria and altered sensorium, in casualty. There is a history of diarrhoea for the past 5 days. The clinical diagnosis is –
Hemolytic uremic syndrome 

HUS is characterized by the triad of -


Anaemia (microangiopathic hemolytic anaemia)
Renal failure (microangiopathy of kidney involving glomerular capillaries and arterioles).
Thrombocytopenia (due to platelet destruction)


HUS is common in children under 2 years of age. (But may also occur in older children).
It usually follows an episode of acute gastroenteritis.
The prodrome is usually of abdominal pain, diarrhoea and vomiting.
Shortly thereafter, signs and symptoms of acute hemolytic anaemia, thrombocytopenia and acute renal failure ensue.
Sometimes neurological findings also occur (But usually absent and differentiates HUS from TTP).
Acute prophyria
Idiopathic thrombocytopenic purpura
H.S. purpura
H.U.S.