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.
Signs and symptoms of multisystem inflammatory syndrome in children (MIS-C) include those below, though not all children have the same symptoms.
- Fever that lasts 24 hours or longer
- Pain in the stomach
- Skin rash
- Feeling unusually tired
- Fast heartbeat
- Rapid breathing
- Red eyes
- Redness or swelling of the lips and tongue
- Redness or swelling of the hands or feet
- Headache, dizziness or lightheadedness
- Enlarged lymph nodes
Emergency warning signs of MIS-C
- Severe stomach pain
- Difficulty breathing
- Pale, gray or blue-colored skin, lips or nail beds — depending on skin tone
- New confusion
- Inability to wake up or stay awake
When to see a doctor
If your child has any of the emergency warning signs listed above — or is severely sick with other signs and symptoms — get care immediately. Take your child to the nearest emergency department or call 911 or your local emergency number.
If your child isn't severely ill but shows other signs or symptoms of MIS-C, contact your child's doctor right away for advice. Doctors may want to do tests — such as blood tests, or imaging tests of the chest, heart or abdomen — to check for areas of inflammation and other signs of MIS-C.
The exact cause of MIS-C is not known yet, but it appears to be an excessive immune response related to COVID-19. Many children with MIS-C have a positive antibody test result. This means they've had a recent infection with the COVID-19 virus. Some may have a current infection with the virus.
In the U.S., more Black and Latino children have been diagnosed with MIS-C compared with children of other races and ethnic groups. Studies are needed to help determine why MIS-C affects these children more often than others. Factors may include, for example, differences in access to health information and services as well as the possibility of risks related to genetics.
Most children with MIS-C are between the ages of 3 and 12 years old, with an average age of 8 years old. Some cases have also occurred in older children and in babies.
Many specialists consider MIS-C to be a complication of COVID-19. Without early diagnosis and appropriate management and treatment, MIS-C can lead to severe problems with vital organs, such as the heart, lungs or kidneys. In rare cases, MIS-C could result in permanent damage or even death.
In the U.S., the Pfizer-BioNTech COVID-19 vaccine is now available to people age 12 and older. A vaccine can prevent you or your child from getting the COVID-19 virus. If you or your child gets COVID-19, a COVID-19 vaccine could or prevent you or your child from becoming seriously ill. Also, if you and your child have been fully vaccinated, you and your child can return to many activities you may not have been able to do because of the pandemic — including not wearing a mask or social distancing — except where required by a rule or law.
If you or your child haven’t been vaccinated, you can take many steps to prevent yourselves from getting the COVID-19 virus and spreading it to others. The CDC recommends following these precautions for avoiding exposure to the virus that causes COVID-19:
- Keep hands clean. Wash hands often with soap and water for at least 20 seconds. If soap and water aren't available, use a hand sanitizer that contains at least 60% alcohol.
- Avoid people who are sick. In particular, avoid people who are coughing, sneezing or showing other signs that indicate they might be sick and contagious.
- Practice social distancing. This means that you and your child should stay at least 6 feet (2 meters) from other people when outside of your home.
- Wear cloth face masks in public settings. When in indoor public places or outdoors where there is a high risk of COVID-19 transmission, such as at a crowded event or large gathering, both you and your child — if he or she is at least 2 years old — should wear face masks that cover the nose and mouth. Further mask guidance differs depending on whether you are fully vaccinated or unvaccinated.
- Avoid touching your nose, eyes and mouth. Encourage your child to follow your lead and avoid touching his or her face.
- Cover your mouth with a tissue or your elbow when you sneeze or cough. You and your child should practice covering your mouths when you sneeze or cough to avoid spreading germs.
- Clean and disinfect high-touch surfaces every day. This includes areas of your home such as doorknobs, light switches, remotes, handles, countertops, tables, chairs, desks, keyboards, faucets, sinks and toilets.
- Wash clothing and other items as needed. Follow manufacturers' instructions, using the warmest appropriate water setting on your washing machine. Remember to include washable plush toys.