Table 1 Classification criteria for Henoch–Schönlein purpura3
Palpable purpura (mandatory) in the presence of at least one of the following four features:

  • Diffuse abdominal pain

  • Arthritis (acute) or arthralgia

  • Renal involvement (any haematuria and/or proteinuria)

  • Any biopsy showing predominant IgA deposition