TY - JOUR T1 - Response to ‘IgA vasculitis in adults: few certainties and many uncertainties’ by Hočevar <em>et al</em> JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - e48 LP - e48 DO - 10.1136/annrheumdis-2018-214951 VL - 79 IS - 4 AU - Alexander Tracy AU - Anuradhaa Subramanian AU - Nicola J Adderley AU - Lorraine Harper AU - Krishnarajah Nirantharakumar Y1 - 2020/04/01 UR - http://ard.bmj.com/content/79/4/e48.abstract N2 - We thank Hočevar and colleagues for their comments on our recently published work on the epidemiology of IgA vasculitis (IgAV) in adults and children.1 2 We agree that there is some uncertainty regarding the incidence of adult-onset IgAV as this has not previously been widely studied.Our calculated incidence of 2.20 (95% CI 2.08 to 2.37) per 100 000 person-years in adults is slightly higher than most previous work has suggested, but is lower than that reported by Hočevar et al in a Slovenian tertiary centre study with no clearly demarcated denominator population.2–4 This disparity may be related to interpopulation differences, for example, in exposure to environmental risk factors such as viral infections.5 Alternatively, the difference may be due to contrasting strategies used to identify cases of IgAV. Hočevar and colleagues used both clinical and … ER -