Is multisystem inflammatory syndrome in children on the Kawasaki syndrome spectrum?

An alarming increase in children presenting with fever, hyperinflammation, and multiorgan dysfunction frequently requiring intensive care has been observed after severe acute respiratory syndrome coronavirus 2 infection. The illness resembles Kawasaki disease (KD), with coronary dilatation and aneurysm occurring in some. However, the cardiovascular manifestations were typically on the severe end of the KD spectrum, with cardiogenic shock a common presentation together with other features. This led to defining a unique syndrome named multisystem inflammatory syndrome in children (MIS-C). In this issue of the JCI, Lee and Day-Lewis et al. and Diorio et al. explored the clinical profiles associated with coronavirus disease 2019 in children. We posit that while splitting MIS-C into a separate disease may aid clinical management decisions, lumping it into the KD pot may better serve to understand pathobiology.