MIS-C is likely to be distinct from Kawasaki disease based on current studies: a narrative review

Background and Objective: Children with SARS-CoV-2 infection were paid little attention to during the early stages of the outbreak because of low morbidity as well as mild clinical symptoms. Since late April 2020, reports regarding Kawasaki-like syndrome and hyperinflammatory response in children associated with COVID-19 have rapidly emerged. Till now, no certain relationship between multisystem inflammatory syndrome in Children (MIS-C) and Kawasaki Disease (KD) has been determined, which should be explored through continuous study. Methods: In order to synthesize key findings for the objectives of this review, we searched English literature published up to November 16, 2020 using PubMed with the following keywords: Kawasaki disease 2020, Kawasaki-like disease, MIS-C, PIMS, PMIS and PIMS-TS. Key Content and Findings: Based on current researches, KD is regarded as an immune disorder induced by multiple unidentified pathogens, while MIS-C is confirmed to be associated with the infection of COVID-19. In addition, KD is popular in East Asian children under 3 years old, while MIS-C is reported more in older adolescents from Europe and North America. On the basis of multiple cohort studies, gastrointestinal symptoms, mechanical ventilation and inotropic support are more common in MIS-C. Instead, coronary arterial damage is more pronounced in KD. Moreover, the treatment regimen for MIS-C is more aggressive than KD because the cytokine storm is more violent and lasting. Conclusions: MIS-C is likely to be a distinct immunopathogenic illness associated with SARS-CoV-2 based on current studies, which could be used as a reference to help us better understand KD. In addition, MIS-C is an emerging syndrome for pediatricians, so the lack of relevant knowledge may result in under-diagnosis. Some individuals may fulfill full or partial criteria for KD but all should be reported if they meet the case definition for MIS-C. © 2022 AME Publishing Company. All right reserved.