Characteristics of Kawasaki Disease Patients during the COVID-19 Pandemic in Japan: A Single-Center, Observational Study

Abstract

Background: Under the Coronavirus disease 2019 (COVID-19) pandemic, manifestations in children with Kawasaki disease (KD) are different between the Western and the Eastern countries. Particularly, there has not been a report comparing a series of KD in Japan, where KD was originally discovered and has a large number of registered cases. Methods: We compared patients with KD under the period of the COVID-19 pandemic in Japan with the report from Italy during its reported period by a retrospective, cohort, observational study in a Japanese single center. Results: Thirty-two patients with typical KD were treated during the study period, while the Italian study reported 10 patients with the signs of KD. Concerning the proof of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, none (0%) of our KD cases showed a positive result and one and no patients developed the macrophage activation syndrome (MAS) and Kawasaki disease shock syndrome (KDSS), respectively; however, eight (80%) patients in the Italian series were confirmed with SARS-CoV-2 infection. MAS and KDSS developed in six and five patients, respectively. Conclusions: Cases reported as COVID-19 pandemic-related KD in Italy showed significantly different clinical characteristics from the typical KD symptoms known in Japan. Although they show KD-like manifestations, we cannot conclude that SARS-CoV-2 has the same etiology of our ‘classic‘ KD at the present stage.

Kawasaki disease following SARS-CoV-2 infection: Stronger inflammation with no increase in cardiac complications

“…In Japan, where the prevalence of KD is high, the incidence of KD or KD-like diseases during the COVID-19 pandemic is not significantly different from that before the COVID-19 pandemic, showing a tendency to decrease (13,14). Although the prevalence of KD is higher than that in Europe and the United States, there have been relatively few reports of MIS-C in Japan (15)(16)(17)(18)(19).…”

“…Recent evidence suggests that young children are at a higher risk of contracting coronavirus disease 2019 (COVID- 19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) than initially expected. In the United States, children and adolescents aged < 18 years accounted for 9% of all COVID-19 cases in 2020, rising to 18.4% by August 2022 (1).…”