MIS-C stands for multisystem inflammatory syndrome in children, a rare and serious inflammatory syndrome that affects children and young adults. It is a new disease that appears to be linked to SARS-CoV-2, the virus which causes COVID-19.
It causes fever and inflammation and can affect different body parts, such as the heart, lungs, kidneys, liver, skin, eyes, brain, and gastrointestinal organs.
MIS-C is very rare. It can be very serious and children usually need to be treated in the hospital.
Causes of MIS-C
We do not know yet exactly what causes MIS-C.
We know that many children with it have been infected with SARS-CoV-2, the virus that causes COVID-19, or have been in contact with someone with COVID-19.
One possibility is that MIS-C is caused by an abnormal immune response to a virus, such as SARS-CoV-2, but this has not yet been confirmed.
We do not know yet why some children have developed MIS-C while others have not or whether there are certain health conditions that increase the risk of MIS-C.
Signs and Symptoms
Because MIS-C can affect different body systems, there are many different symptoms and no two cases are exactly alike.
The most commonly reported symptoms are:
Feeling extra tired
Patients with MIS-C have persistent fever (sometimes for 3 or 4 days) and evidence of inflammation in one or more organ systems, including gastrointestinal, heart, lungs, kidneys, brain and skin. Often these children will have abdominal pain or vomiting and diarrhea. They may have excessive fatigue.
MIS-C shares some of the same features of Kawasaki’s disease, which usually affects children under 5 and causes rashes and inflammation of the coronary arteries, along with swelling of the hands, feet and lymph nodes. It is not known whether these two conditions are related. Some findings in MIS-C are similar to a type of toxic shock syndrome seen with staph or strep bacteria. Some children with MIS-C may test positive for the SARS-Cov-2 virus or have antibodies to the SARS-CoV-2 virus.
There is no specific test to diagnosis MIS-C. The diagnosis is made using a combination of signs and symptoms along with blood tests. Some children need imaging tests such as echocardiograms of their heart to look for signs of inflammation. Some children with MIS-C test positive for SARS-CoV-2, the virus that causes COVID-19, using a nasal swab or an antibody test, but not all.
Because MIS-C can mimic other diseases that occur in children, doctors have been using some of the same treatments as these diseases, such as steroids or other medicines that reduce inflammation or medicines that increase blood pressure.
Some children need to be monitored or treated in the hospital, but the majority of children diagnosed with MIS-C do well and deaths are uncommon.
Based on what we know so far about MIS-C, the best way to protect children is for us all to take preventive actions to reduce the spread of the virus that causes COVID-19, such as staying at least 6 feet from people (social distancing), washing your hands often, and wearing a face covering in public.
Information for Parents
What to do if you think your child has MIS-C
If your child is showing any of the symptoms of MIS-C, especially if they have been diagnosed with COVID-19 in the past or been in contact with someone who has, call your health care provider right away.
If your child is having trouble breathing, pain or pressure in their chest, new confusion, bluish lips or face, severe abdominal pain, or you cannot wake them up, seek emergency care right away.
School and child care
This syndrome is extremely rare and outcomes are generally good. Parents should certainly be alert for it as a possibility if their child becomes ill because COVID-19 is still circulating in communities, but you do not need to keep your child home from a setting like school or child care unless they are sick or were in close contact with someone who has COVID-19.
Information for Health Care Providers
Health care providers can report MIS-C cases to MDH at firstname.lastname@example.org.
AskMayoExpert: COVID-19: Multisystem inflammatory syndrome in children (MIS-C) MIS-C triage, diagnosis, and clinical care flowchart algorithm from Mayo Clinic.
More about MIS-C
CDC: Multisystem Inflammatory Syndrome in Children (MIS-C)
CDC Health Alert Network: Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with Coronavirus Disease 2019 (COVID-19)