BACKGROUND: An outbreak of multisystem inflammatory syndrome in children, including Kawasaki disease (KD), emerged during COVID-19 pandemic . We explored whether Kawasaki-like disease (KD), when associated with confirmed SARS-CoV-2 infection, has specific characteristics .
METHODS: We included children and adolescents with KD criteria admitted in the department of general pediatrics of a university hospital in Paris, France, between January 1 , 2018, and May 26 , 2020 . The incidence of KD was compared between the outbreak and a pre-outbreak control period (January 1 , 2018, to April 25). Characteristics of patients with positive SARS-CoV-2 testing (KD-SARS-CoV-2) were compared to those of the pre-outbreak period (classic KD).
RESULTS: A total of 30 and 59 children with KD were admitted during the outbreak and pre-outbreak periods, respectively (incidence ratio 13.2 [8.3-21.0] ). During the outbreak , 23/30 (77 %) children were diagnosed as KD-SARS-CoV-2 . When compared with patients with classic KD, those with KD-SARS-CoV-2 were more frequently of sub-Saharan African ancestry (OR 4.4 [1.6-12.6] ) and older (median 8.2 vs. 4.0 years, p <0.001), had more often initial gastrointestinal (OR 84 [4.9-1456] ) and neurological (OR 7.3 [1.9-27.7] manifestations, and shock syndrome (OR 13.7 [4.2-45.1] ). They had significantly higher CRP and ferritin levels . Noticeably, they had more frequently myocarditis (OR 387 [38-3933] ).
CONCLUSIONS: Children and adolescents with KD-SARS-CoV-2 have specific features when compared with those with classic KD . These findings should raise awareness and facilitate the study of their pathogenesis.