Table 3 Classification criteria for Henoch‐Schönlein purpura.

Palpable purpura (mandatory criterion) in the presence of at least one of the following four features:

• Diffuse abdominal pain

• Any biopsy showing predominant IgA deposition

• Arthritis* or arthralgia

• Renal involvement (any haematuria and/or proteinuria)

*Acute, any joint.