Objective In this study, our objective is to compare the demographic, clinical, laboratory, and echocardiographic findings of patients with multisystem inflammatory syndrome in children (MIS-C) and Kawasaki's disease (KD) diagnosed in the prepandemic period.

Methods We retrospectively collected data from all pediatric patients who met the Centers for Disease Control and Prevention's MIS-C case definition and who met the American Heart Association's definition of complete KD before the coronavirus disease 2019 pandemic.

Results A total of 37 patients diagnosed with MIS-C and 40 patients diagnosed with complete KD were included. Gastrointestinal findings were significantly higher in the MIS-C group than in the KD group (vomiting [p = 0.009], diarrhea [p = 0.009]). The incidence of thrombocytopenia (48.6%) was significantly higher in the MIS-C group. Regarding inflammatory markers, procalcitonin and ferritin were significantly higher in the MIS-C group (p = 0.032 and p = 0.006) and the erythrocyte sedimentation rate was higher in the KD group (p < 0.001). Pericardial effusion and mitral valve regurgitation were significantly more frequent in the MIS-C group (p = 0.024 and p = 0.001).

Conclusion Although they have similar findings, our current study findings show that MIS-C and KD differ from each other with different clinical and laboratory features. We think that these differences will help clinicians in diagnosis and patient management.

Received: 24 November 2023

Accepted: 21 May 2024

Article published online:
19 July 2024

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