A: MIS-C, or Multisystem Inflammatory Syndrome in children, is possible when kids with COVID-19 get really sick and different body parts (like the lungs, heart, kidneys, brain, or gut) become inflamed and damaged.
It is a rare, but very serious, medical problem. Though kids are less likely to get seriously ill from COVID-19, as the pandemic continues more children are getting infected and at risk of developing MIS-C. When there are more cases of COVID-19 in our communities, there are more cases of MIS-C.
Certainly not every child who gets #COVID-19 will develop #MIS-C, a severe form of illness that can be dangerous and life-threatening. As of March 29, 2021, there have been 3,185 confirmed cases (with many more under investigation) and 36 deaths in the US. Most cases are diagnosed in kids age 1 to 14, with a median age of 9 years old. Just like in adults, this disproportionately affects children who are Hispanic or Latino and Black.
MIS-C is diagnosed when someone under the age of 21 with COVID-19 infection has a fever, lab testing showing inflammation, severe illness requiring hospitalization, and at least 2 different organ systems showing damage. Organs like the heart, kidneys, lungs, intestines and stomach, skin, or brain might be involved. People who have MIS-C often have abdominal pain, vomiting, diarrhea, rash, and may even have dangerously low blood pressure or shock. It can develop weeks after getting COVID-19, even in kiddos who didn’t have any symptoms initially from the COVID-19 infection. MIS-C can be confused with another childhood illness, called Kawasaki disease. They both have similar symptoms, but children with MIS-C are more likely to have gut and neurologic symptoms, more likely to have shock, and more likely to have the heart involved.
No one really knows why some children develop MIS-C. One common hypothesis is that that immune system goes into overdrive, even after the infection itself has cleared up. This is why the treatment involves modulating the immune system, like steroids or antibody treatment given through the veins (IVIG). These treatments can help keep the body’s immune system from attacking itself. Because damage to the heart is common, these children also get an ultrasound of the heart (called an echocardiogram) and an EKG (a test that looks at the electrical activity of the heart). Blood testing is done to check on the liver, kidneys, and blood function. Children might need intravenous (IV) fluids to help keep their blood pressure up to normal levels or they may need help breathing.
We don’t yet know what the long-term complications will be for kids who had MIS-C. These kiddos should be seen early and often by their primary care clinician to look out for problems and a heart doctor who specializes in children.
Caregivers of children should get immediate medical attention for kids with severe stomach pain, difficulty breathing, new confusion, inability to wake up, or new pale, gray or blue-colored skin, lips or nail beds.
For more information on MIS-C, check out:
The US Centers for Disease Control and Prevention (CDC) website on MIS-C
US Health Department Reported Cases of MIS-C
American Academy of Pediatrics MIS-C Interim Guidance
American College of Rheumatology Clinical Guidance on MIS-C
International Data on MIS-C symptoms published in AAP Pediatrics
