Kawasaki disease in children with Bacillus Calmette-Guérin scar reactivity: Focus on coronary outcomes

Abstract

Background/Purpose: Reactivity at the Bacillus Calmette-Guérin (BCG) scar is a pathognomonic feature of Kawasaki disease (KD). However, its value in predicting KD outcomes has not been emphasized. This study explored the clinical significance of BCG scar redness with respect to coronary artery outcomes. MethodsThis retrospective study collected data on children with KD from 13 hospitals in Taiwan during 2019–2021. Children with KD were categorized into four groups based on the KD type and BCG scar reactivity. Risk factors of coronary artery abnormalities (CAA) were analyzed in all groups. ResultsBCG scar redness occurred in 49% of 388 children with KD. BCG scar redness was associated with younger age, early intravenous immunoglobulin (IVIG) treatment, hypoalbuminemia, and CAA at the first echocardiogram (p < 0.01). BCG scar redness (RR 0.56) and pyuria (RR 2.61) were independent predictors of any CAA within 1 month (p < 0.05). Moreover, pyuria (RR 5.85, p < 0.05) in children with complete KD plus BCG scar redness was associated with CAA at 2–3 months; first IVIG resistance (RR 15.2) and neutrophil levels ≥80% (RR 8.37) in children with complete KD plus BCG scar non-redness were associated with CAA at 2–3 months (p < 0.05). We failed to detect any significant risk factors of CAA at 2–3 months in children with incomplete KD. ConclusionBCG scar reactivity contributes to diverse clinical features in KD. It can be effectively applied to determine the risk factors of any CAA within 1 month and CAA at 2–3 months.