To report the epidemiologic characteristics, treatments, and cardiac complications of KD, using data from the nationwide survey in Japan.
The nationwide KD survey in Japan has been conducted biennially since 1970. The most recent survey was completed in 2019, obtaining information for patients who developed KD during 2017-2018. Survey respondents were hospitals specializing in pediatrics and those with ≥100 beds and a pediatric department throughout Japan, where patients with Kawasaki disease were eventually hospitalized.
The survey identified 32528 patients with Kawasaki disease, which consisted of 15164 (46.6%) in 2017 and 17364 (53.4%) in 2018. The highest annual incidence rate was recorded in 2018 (359 per 100,000 children aged 0-4 years). After 1982, patients with ≤4 principal KD signs gradually increased, resulting in 6847 (21.1%) patients diagnosed during 2017-2018. Among 30784 patients receiving initial intravenous immunoglobulin administration, 6061 (19.7%) did not respond. Within 30 days of KD onset, 9.0% of patients were diagnosed with cardiac complications, and consequently, 2.6% of patients developed cardiac sequelae after the acute illness.
The annual number of patients developing KD in Japan increased from 1970 through 2018, while the proportion of patients with Kawasaki disease with cardiac complications decreased in the most recent two decades. Early diagnosis of KD as well as advances in initial treatments could explain these findings.

Copyright © 2020. Published by Elsevier Inc.