Epidemiology of the vasculitides

Systemic vasculitides constitute a heterogeneous group of overlapping disea ses characterized by blood vessel inflammation and necrosis. Although the c auses of most forms of vasculitis are unknown, epidemiological studies have implicated geographic, genetic, and environmental factors. Ethnicity, vari ous genes such as those of the Major Histocompatibility Complex, gender, an d environmental factors appear to account for differences in the incidence of these syndromes. In this article, the authors focus on the incidence of these conditions in different parts of the world and on the influence of en vironmental and genetic factors.