Henoch-Schonlein purpura (HSP) is an IgA mediated small vessel vasculitis. There is a degree of overlap with IgA nephropathy (Berger's disease). HSP is usually seen in children following an infection.
Features
- palpable purpuric rash (with localized oedema) over buttocks and extensor surfaces of arms and legs
- abdominal pain
- polyarthritis
- features of IgA nephropathy may occur e.g. haematuria, renal failure
Differentials:
- polyarteritis nodosa
- juvenile rheumatoid arthritis
- acute hemorrhagic edema of infancy
- Wegener granulomatosis
- meningococcemia
- Kawasaki disease
- thrombocytopenic purpura
Investigations
Initial investigations: