CUTANEOUS VASCULITIS IN A DEFINED POPULATION - CLINICAL AND EPIDEMIOLOGIC ASSOCIATIONS

Objective. To examine the value of the American College of Rheumatolog y (ACR) 1990 criteria for Henoch-Schaolein purpura (HSP) and hypersens itivity vasculitis (HSV) and the Chapel Hill Consensus Conference (CHC C) definition of cutaneous leukocytoclastic angiitis (CLA) in the clas sification of cutaneous vasculitis and to estimate the annual incidenc e of biopsy proven cutaneous vasculitis in a well defined population. Methods. ACR criteria for HSP and HSV and the CHCC definition for CLA and HSP were applied to an unselected cohort of 84 patients with biops y proven cutaneous vasculitis attending a single district hospital in the United Kingdom between January 1990 and December 1991. Results. Th irty-seven patients fulfilled ACR criteria for HSV, of whom 27 also fu lfilled the ACR criteria for HSP. Thirty-two patients met the CHCC def inition for CLA and 7 the CHCC definition for HSP. The overall annual incidence of cutaneous vasculitis was 38.6/million (95% CI 30.6-48.1), and for CLA 15.4/million (95% CI 10.6-21.8). Conclusion. The ACR 1990 criteria for HSP and HSV overlap: the CHCC definitions for CLA and HS P provide cleans distinction. Cutaneous vasculitis is as common as sys temic vasculitis.