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

BackgroundHerein we investigate the difference between Kawasaki disease (KD) with and without a recent history of SARS-CoV-2 infection.MethodsWe compared the clinical characteristics of patients with KD during the SARS-CoV-2 pandemic in a single children's hospital in Korea. Fifty-two patients were enrolled and divided into group 1 (with a history of COVID-19, n = 26) and group 2 (without a history of COVID-19, n = 26) according to whether or not they contracted COVID-19 within the 8 weeks before hospitalization. Data, including clinical features and laboratory results, were analyzed and compared between groups.ResultsThe median age of patients was significantly higher in group 1 than in group 2 (53 months [IQR, 24–81] vs. 15 months [IQR, 6–33], p = 0.001). The incidence of cervical lymphadenopathy was significantly higher (p = 0.017), while that of BCGitis was significantly lower in group 1 (p = 0.023), and patients had a significantly longer hospital stay (5 days [IQR, 3–8] vs. 3 days [IQR, 3–4], p = 0.008). In group 1, platelet count was significantly lower (p = 0.006), and hemoglobin and ferritin levels were significantly higher (p = 0.013 and p = 0.001, respectively) on the first admission day. Following treatment with intravenous immunoglobulin (IVIG), the platelet count was significantly lower (p = 0.015), and the percentage of neutrophils and neutrophil-to-lymphocyte ratio were significantly higher in group 1 (p = 0.037 and p = 0.012). Although there was no statistical difference, patients requiring infliximab treatment due to prolonged fever was only in group 1. The incidence of cardiovascular complications did not differ between the groups.ConclusionsPost-COVID KD showed a stronger inflammatory response than KD-alone, with no differences in cardiac complications.