Aim: To determine the effect of a severe cyclone on incidence and clinical phenotype of Anti‐neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) in Central Queensland, Australia.

Background: Environmental pollution due to natural disasters may be associated with AAV. To date, there have been no studies assessing any correlation between cyclones and incidence of AAV.

Methods: Retrospective observational single region study of all AAV within 3 years pre‐ and post‐cyclone Marcia which occurred on 20th February 2015.

Results: The incidence of AAV increased from one case (1.5 cases per million person years) during the three years prior to the cyclone to 10 cases (15.1 cases per million person years) during three years after (incidence rate ratio: 10.0, 95% confidence interval: 1.4 to 444.0, p = 0.006). There was one case of relapse of previously diagnosed AAV during our study period. The mean age of AAV was 71.7 years with Caucasian (n = 9, 90%) and male predominance (n = 6, 60%). MPO‐AAV (n = 6) was more common than PR3‐AAV (n = 1) in this study. The incidence peaked in the first year following the cyclone (8 cases), with one case in the second year followed by another case in the third year. Only two patients (20%) had pulmonary complications. Five patients (50%) lived in the vicinity of a mining area, and four (40%) had occupations involving mining, farming or construction. The majority were pet keepers (n = 7, 70%). Medications and infections were not implicated in our study group.

Conclusions: This study suggested an association between a category V cyclone and increased incidence of AAV. Further multicentre studies are necessary to strengthen evidence supporting this theory which will shed more light on the aetiology of AAV.