Purpura or petechiae

and at least one of the following:

(Mandatory criterion) with lower limb predominance

1) Abdominal pain

2) Histopathology

Typically leukocytoclastic vasculitis with predominant IgA deposit or proliferative glomerulonephritis with predominant IgA deposits.

3) Acute onset of arthritis or arthralgia

Defined as joint swelling or joint pain with limitation on motion or joint pain without joint swelling or limitation on motion.

4) Renal involvement

Defined as proteinuria > 0.3 g/24h or >30 mmol/mg of urine albumin/creatinine ratio on a spot morning sample, hematuria or red blood cell casts > 5 red blood cells/high power field or red blood cells casts in the urinary sediment or ≥2+ on dipstick.