Multisystem inflammatory syndrome in children (MIS-C) and COVID-19: a review of the literature

Abstract

Multisystem Inflammatory Syndrome in Children (MIS-C) is a novel pediatric hyperinflammatory syndrome that has recently emerged globally as a potential complication of COVID-19 infection and has features similar to Kawasaki Disease (KD). In this article, a review existing literature on MIS-C was conducted to identify trends in patient characteristics, clinical and biological features, treatment, and outcomes. MIS-C affects previously healthy school-age children, with over-representation of those of Black and Afro-Caribbean descent. It presents with fever, gastrointestinal complaints, and KD-type features including rash and conjunctivitis. Laboratory and imaging studies demonstrate evidence of systemic inflammation and myocarditis. Accordingly, children are often critically ill and require intensive care admission and organ support. However, prompt anti-inflammatory treatment with intravenous immunoglobulin, steroids, and aspirin appears to lead to favourable outcomes. Though evidence of current coronavirus infection by RT-PCR is variable, most children have positive serology results indicating prior infection, which supports theories of MIS-C as a dysfunctional post-infectious immune process. Though similar to KD in some ways, MIS-C has important differences in its patient characteristics, clinical features, and cardiac involvement. Large-scale case registries and analysis of resulting data will be crucial to refining our understanding of MIS-C to ensure optimal outcomes for children worldwide.