Immunoglobulin A vasculitis (IgAV), formerly called Schonlein-Henoch purpura, belongs to immune complex small vessel vasculitis. IgAV is the most common vasculitis in childhood but is more rare in adults [1,2]. To date, very few epidemiological studies have addressed the incidence of IgAV (n=6) (Table 1). Most studies have used monocentric patient hospital register or discharge diagnosis codes as the source of case identification, including patients who fulfilled pre-specified criteria, resulting in an annual incidence rate of 0.34–5.1/100,000 adults [3–8].
