Kawasaki disease in adults: observations in France and literature review Short title: Kawasaki disease in adults in France

International audience; Objective Kawasaki disease (KD) is a vasculitis that mostly occurs in young children and rarely in adults. We analyzed the characteristics of adult-onset KD (AKD) in France. Methods We collected retrospective and prospective data for patients with a diagnosis of KD occurring after the age of 18 years. Cases were obtained via various French medical networks and identified from the international literature. Results We included 43 patients of AKD at 26 institution from 1992 to 2015, with mean (SD) age 30 (11) years (range 18–68) and sex ratio (M/F) 1.2; 34 patients met the American Heart Association criteria and 9 were incomplete AKD. The median time to diagnosis was 13 days (interquartile range 8–21). The main symptoms were fever (100%), exanthema (98%), changes in the extremities (91%), conjunctivitis (77%), oral cavity changes (89%), cervical adenitis (55%) and cardiac abnormalities (45%). Overall, 35% of patients showed large-vessel vasculitis: coronary vasculitis (26%) and coronary aneurysm (19%). Treatment was mostly intravenous immunoglobulins (79%) and aspirin (81%). Four patients showed myocardial infarction due to coronary vasculitis, but none were treated with IVIg because of late diagnosis. After a median follow-up of 5 months (range 1–117), persistent aneurysm was noted in 9% of cases. Damage was significantly lower with early treatment than late or no treatment (p = 0.01). Conclusion Given the high frequency of cardiac involvement and complications in this series of AKD, diagnosis and treatment should not be delayed, and early IVIg treatment seems to improve the outcome