A 7 year old unwell child presents with a diarrhoeal illness. Her FBC and UEC show anaemia, thrombocytopaenia and renal failure. There is evidence of infection ( elevated WCC). These results are classic of 

Haemolytic Uraemic syndrome

Other DDX include:

Inflammatory Bowel disease

HSP

Intussusception

Sepis

TTP

Vasculitis

Investigations:

Blood film – Schistocytes (fragmented RBC)

urine – Protein, blood

Blood Cultures, stool cultures

Haemolysis (MAHA) – elevated LDH, low haptoglobin, elevated plasma free Haemoglobin (this mops up the haptoglobin), elevated unconjugated bilirubin.

Coombs test -ve => non immune cause

Coagulation Profile – normal PT, PTT (excludes DIC)

HUS – commonest cause of acute renal failure in childhood

Cause:

Infection – E Coli 0157:H7 (also O104:H4); Shigella, Campylobacter, pneumococcal, viruses

Agent – Shiga toxin or shiga like toxin is thought to be the main agent involved

Source – contaminated water or foodborne

Treatment – supportive, dialysis, plasmapheresis

Prognosis – high mortality during acute phase (up to 25%), up to 50% may develop CRF