Criteria and Definitions Used for the Classification of Hypersensitivity Vasculitis

1. Age at disease onset >16 years

Development of symptoms after age 16

2. Medication at disease onset

Medication was taken at the onset of symptoms that may have been a precipitating factor

3. Palpable purpura

Slightly elevated purpuric rash over one or more areas of the skin; does not blanch with pressure and is not related to thrombocytopenia

4. Maculopapular rash

Flat and raised lesions of varous sizes over one or more areas of the skin

5. Polymorphonuclear neutrophils in vessel wall

Biopsy demonstrating granulocytes in the wall of a venule or arteriole

6. Eosinophils in biopsy

Biopsy demonstrating eosinophils in a venule or arteriole at any location

* This is criterion 19 from Table 1.
+ This is criterion 21 from Table 1.