Epidemiology

The epidemiology of the systemic vasculitides varies greatly according to the type of vasculitis and the patient's age, sex, and geographical location.[3] The absence of a universal classification system for vasculitis further complicates collection and analysis of epidemiological data.[4]​ 

In general, vasculitis is most common at extremes of age, i.e., in young children and older adults.[4]​

Giant cell arteritis, a form of large-vessel vasculitis, is most often seen in adults older than 50 years of age and in those of Northern European ancestry.[4] A Swedish study found that the incidence rate of GCA increased dramatically from 2.0 per 100,000 in those aged 50-60 years to 31.3 per 100,000 in those aged 71-80 years.[5]​​

Kawasaki disease, a form of medium-vessel vasculitis, almost exclusively affects young children (<5 years of age). The majority of cases occur in East Asia, specifically Japan, South Korea, and China.[4]​

Forms of anti-neutrophil cytoplasmic auto-antibody (ANCA)-associated vasculitis are more common with increasing age, whereas IgA vasculitis, another type of small-vessel vasculitis, is most frequently seen in children and adolescents.[4]​

The reason for geographical variation in the prevalence of vasculitis remains a source of debate. Potential aetiological factors such as seasonality, infectious triggers, and environmental toxins have all been proposed, but robust evidence remains lacking.[4]​

Use of this content is subject to our disclaimer