Differences in the Clinical Characteristics of Kawasaki Disease Between Older and Younger Children (2015-2019): A Single-Center, Retrospective Study.

OBJECTIVE: The objective of this study was to investigate the differences in the clinical characteristics of Kawasaki disease between older and younger children. STUDY DESIGN: This retrospective study examined 405 children with Kawasaki disease admitted to Showa University Northern Yokohama Hospital between 2015 and 2019. RESULTS: Eligible patients were classified into the older (≥3.0 years of age, n = 169) and younger (<3.0 years of age, n = 236) groups. Skin rash was found in significantly fewer cases (112 [66.3%] vs 229 [97.0%], P < .001 in the younger group). Cervical lymphadenopathy was more common in older children (153 [90.5%] vs 165 [69.9%], P < .001) and in incomplete Kawasaki disease (3 or 4 findings) (34 [20.1%] vs 25 [10.6%], P = .0078). The diagnosis was more delayed in older children (median: 5.0 days vs 4.0 days, P = .003) than the younger group. Additionally, fever nonresponsive to a single intravenous immunoglobulin was more common, and the duration of fever was significantly longer in the older group (48 [28.4%] vs 47 [19.9%], P = .0479). CONCLUSIONS: Kawasaki disease should be suspected in children aged >3.0 years with cervical lymphadenopathy and fever, despite the absence of skin rash. Additionally, incomplete Kawasaki disease, fever unresolved by a single intravenous immunoglobulin infusion, and the tendency to delay treatment initiation are more common in children aged >3.0 years.