Kawasaki disease in the pre- and post-COVID-19 era: shifts in patterns and outcomes from a multi-center study

Kawasaki disease (KD) is an acute vasculitis of childhood, with potential complications such as coronary artery aneurysms (CAAs). The COVID-19 pandemic introduced challenges in KD diagnosis and management due to its overlap with multisystem inflammatory syndrome in children (MIS-C). This study aims to compare the clinical presentation, laboratory findings, treatment approaches, and outcomes of KD before and after the COVID-19 pandemic across four centers in the United Arab Emirates (UAE).

This retrospective study analyzed pediatric KD cases (classified per the American Heart Association "AHA" criteria) from four tertiary hospitals in the UAE. Patients were categorized into group 1 (pre-COVID-19: January 2017-January 2020) and group 2 (post-COVID-19: February 2020-January 2023). Patients not meeting the AHA criteria and those with MIS-C were excluded. Data collection included demographics, clinical and laboratory features, and echocardiograms, with coronary artery abnormalities assessed per AHA guidelines.

Among 138 included patients (67 in group 1, 71 in group 2), incomplete KD was significantly more common post-COVID-19 (45% vs. 25%, p = 0.020). Lower occurrence of cervical lymphadenopathy (72% vs. 50%, p = 0.009) and strawberry tongue (90% vs. 70%, p = 0.006) were noted. Compared to group 1, group 2 had higher use of steroids (40.8% vs. 12.5%, p =  < 0.001) and biologics (8% vs. 1.5%, p = 0.502). Although not statistically significant, CAAs were more frequent in group 2 (21% vs. 10%, p = 0.139), with trends toward increased giant CAAs.

Our study highlights shifts in the patterns of KD in the post-COVID-19 era. We observed a higher prevalence of incomplete KD cases over the 3 years following the pandemic.

• Post-COVID-19 pandemic era demonstrated the emergence of multi-system inflammatory syndrome in children (MIS-C) which overlaps with Kawasaki disease (KD). • While most studies of KD and COVID-19 compare KD with MIS-C, very few describe changes in KD well after the peak of the pandemic.

• This study combines data from four healthcare centers of KD patients classified per the American Heart Association (AHA) criteria with the exclusion of MIS-C patients to provide direct comparison of KD before and after COVID-19. • Compared to the pre-COVID-19 era, KD cases post-COVID-19 tend to present in an incomplete form with less occurrence of cervical lymphadenopathy and strawberry tongue.