Multisystem Inflammatory Syndrome in Children: A Year in Review

Centers for Disease Control and Prevention published a case definition for the multisystem inflammatory syndrome in children in May 2020 when reports started pouring in about a clinical syndrome in children which was temporally associated with coronavirus disease 2019 infection. It has also been referred to as pediatric inflammatory multisystemic syndrome temporally associated with severe acute respiratory syndrome coronavirus 2. Most of these patients test positive for severe acute respiratory syndrome coronavirus 2 serology or reverse transcription-polymerase chain reaction, although a small number of patients could test negative which would require an epidemiological link to the coronavirus disease 2019 infection. The initial clinical presentation could overlap with Kawasaki disease, severe coronavirus disease 2019 infection, toxic shock syndrome, and macrophage activation syndrome. While multisystem inflammatory syndrome in children is characterized by multisystem involvement with hyper inflammation and severe clinical presentation initially, the prognosis is generally good. Since it was first described, there have been multiple studies describing the demographic characteristics, laboratory features, and treatment paradigm.