Overview

Multisystem inflammatory syndrome in children (MIS-C) is a serious condition that appears to be linked to coronavirus disease 2019 (COVID-19). Most children who become infected with the COVID-19 virus have only a mild illness. But in children who go on to develop MIS-C, some organs and tissues — such as the heart, lungs, blood vessels, kidneys, digestive system, brain, skin or eyes — become severely inflamed. Signs and symptoms depend on which areas of the body are affected.

MIS-C is considered a syndrome — a group of signs and symptoms, not a disease — because much is unknown about it, including its cause and risk factors. Identifying and studying more children who have MIS-C may help to eventually find a cause. The U.S. Centers for Disease Control and Prevention (CDC) and the National Institutes of Health are working with doctors and researchers across the country to learn more about risk factors for MIS-C, share data, and improve diagnosis and treatment of MIS-C.

Rarely, some adults develop signs and symptoms similar to MIS-C. This new and serious syndrome, called multisystem inflammatory syndrome in adults (MIS-A), occurs in adults who were previously infected with the COVID-19 virus and many didn't even know it. MIS-A seems to occur weeks after COVID-19 infection, though some people have a current infection. If MIS-A is suspected, a diagnostic or antibody test for COVID-19 can help confirm current or past infection with the virus, which aids in diagnosing MIS-A.

MIS-C is rare, and most children who have it eventually get better with medical care. But some kids rapidly get worse, to the point where their lives are at risk.

Much remains to be learned about this emerging inflammatory syndrome. If your child shows any signs or symptoms, get help fast.