Kawasaki Disease (KD) is a child vasculitis. The prognosis is associated with a higher risk of coronary artery aneurysm (CAA). Currently the main goal of treatment consists of preventing CAA. At first the treatment consists on immunoglobulin (IVIG). The last American 2016 guidelines recommends echographical coronary diameter express as z-score. The epidemiology of KD is not well known in France. The aim of this study was to describe the population of the children in a region of North of France and to look for risk factors of CAA.

We included patients with KD who were admitted in hospital centers of the region from 2006 to 2016. We reviewed retrospectively the medical, biological and echographical records and their monitoring data. We compared patients in group with and without CAA at 4 weeks from the diagnosis.

We included 240 children from 6 hospital centers. The median age was 28 months (14–50), 20% were less than 1 year old. The male-to-female ratio was 1.8. Diagnosis was done after 7 days of fever at mean. We found 87 children with initial z-score≥2DS and 28 with CAA. Patients were treated with IVIG and 35 get more than one cure, 95% get aspirin for anti-inflammatory then 87% as antiplatelet therapy. Five received corticosteroids, 1 an anti-TNFα and 1 an anti-IL1. Risk scores of CAA from Kobayashi, Egami and Sano present low sensitivity and low specificity. Several risk factors were associated with CAA: age<6 months (OR=4, P=0.05), IVIG resistance (OR=3.6, P=0.007), z-score≥2DS at diagnosis (OR=6.7, P=0.09 10⁻⁴) and platelet count (Pq)≥444 G/L (P=0.04). Only the initial z-score≥2 DS (P=0.02) and Pq ≥ 444 G/l (P=0.04) were significant in multivariate analysis.

The Japanese risk scores were not significant in the French population, as previously shown in North American or English populations. The initial z-score≥2 DS is a good risk factor of CAA so is the Pq≥444 G/l after the day 7th of fever in our population.