It is the most common primary systemic vasculitis in children. Diagnosis requires the presence of purpura or petechiae with lower limb predominance with one of the following four-
- Abdominal pain
- Arthritis or Arthralgia
- Renal involvement(proteinuria or haematuria or presence of red blood cell casts)
- Histopathology showing typical leukocytoclastic vasculitis with predominant IgA deposits.
Complications include orchitis, intussusceptions and intestinal perforation. It is generally a self limiting illness, however, recurrence is seen in one-third of patients. Recurrence generally occurs within four months of resolution of the original symptoms. Renal involvement is the most serious long-term complication and can occur upto 6 months from the presentation. This can be easily picked up by a regular urine examination every 15 days for presence of proteinuria and RBCs.
Prednisolone (1 mg/kg per day for 2 weeks, with weaning over the subsequent 2 weeks) is effective in reducing the intensity of abdominal pain and joint pains. It does not prevent the development of renal complications, however, it is used in treating them.