Diagnosis

Multisystem inflammatory syndrome in children (MIS-C) diagnosis is based on a child's symptoms and on ruling out similar conditions. Lab tests can help this process.

Providers rule out active cases of COVID-19 by testing for the virus with a swab of the nose. They also may swab the back of the throat. Providers also use blood tests to rule out inflammatory conditions such as Kawasaki disease, sepsis or toxic shock syndrome.

Many children with MIS-C test negative for a current infection with the COVID-19 virus. But proof of a prior infection can be gathered from an antibody test if a child had COVID-19 but didn't have any symptoms. It also can be collected by noting infections among a child's close contacts. Most kids who get MIS-C have a link to the virus that causes COVID-19 within 2 months of getting sick.

Providers also may order tests to look for inflammation and other signs of MIS-C:

  • Lab tests, such as blood and urine tests, including tests for the level of an inflammatory protein in the blood.
  • Imaging tests, such as a chest X-ray, an echocardiogram, an abdominal ultrasound or a CT scan.
  • Other tests, depending on symptoms.

More Information

Treatment

Children with MIS-C are treated in a hospital. Some need treatment in a pediatric intensive care unit. Treatment is supportive care and efforts to lower inflammation in any affected vital organs to protect them from permanent damage. Treatment depends on the type and severity of symptoms and which organs and other parts of the body are affected by inflammation.

Supportive care may include:

  • Fluids, if levels are too low, a condition called dehydration.
  • Oxygen to help with breathing.
  • Blood pressure medicines to treat low blood pressure related to shock or to help with heart function.
  • A breathing machine called a ventilator.
  • Medicines that lower the risk of blood clots, such as aspirin or heparin.
  • In very rare cases, extracorporeal membrane oxygenation (ECMO) using a machine that does the work of the heart and lungs.

Treatment to limit swelling and inflammation may include:

  • Antibiotics.
  • Steroid therapy.
  • Intravenous immunoglobulin (IVIG), a blood product made up of antibodies.
  • Other types of treatment, such as targeted therapies aimed at lowering high levels of proteins called cytokines, which can cause inflammation.

There is no proof that MIS-C is contagious. But there's a chance that your child could have an active infection with the COVID-19 virus or another type of contagious infection. So the hospital will use infection control measures while caring for your child.

Coping and support

If your child is seriously ill with MIS-C, you may feel overwhelming anxiety and fear. Because MIS-C is rare, you likely don't know anyone who has been through this experience. To help cope with the emotional toll this can take, ask for support. This can range from discussing your feelings with loved ones and friends to asking for help from a mental health professional. Ask your health care team for advice. For your own sake and that of your child, don't try to handle this anxiety and distress by yourself.

Preparing for your appointment

If your child has emergency warning signs of MIS-C or is severely sick, take your child to the nearest emergency department. Or call 911 or your local emergency number. Remember to wear a mask to protect yourself and others.

If your child's symptoms are not severe, contact your child's pediatrician or other health care professional. The provider may want to assess your child or refer you to a provider who specializes in infectious diseases.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance. Make a list of:

  • Your child's symptoms, including when they started.
  • Key personal information, including major stresses, recent life changes and family medical history.
  • All medicines, vitamins or other supplements your child takes, including the dosages.
  • Any group activities your child recently took part in, including the dates.
  • Questions to ask the health care professional.

What to expect from your doctor

Your health care professional is likely to ask you, and your child, depending on your child's age, several questions, such as:

  • When did the symptoms begin?
  • How severe are the symptoms?
  • Has your child been tested for COVID-19?
  • Has your child been exposed to anyone who tested positive for the COVID-19 virus?
  • Does your child go to school?
  • Has your child been involved in any recent group activities, such as sports?
  • Who has your child been in close contact with recently?

Preparing for the appointment makes sure you have time to get all of your questions answered. It helps you learn what the next steps are and why they're important.

July 22, 2023
  1. For parents: Multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. Centers for Disease Control and Prevention. https://www.cdc.gov/mis/mis-c.html. Accessed Dec. 20, 2022.
  2. Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19). Centers for Disease Control and Prevention. https://emergency.cdc.gov/han/2020/han00432.asp. Accessed Dec. 30, 2022.
  3. Living guidance for clinical management of COVID-19. World Health Organization. https://www.who.int/publications/i/item/WHO-2019-nCoV-clinical-2021-2. Accessed Dec. 30, 2022.
  4. AskMayoExpert. Multisystem inflammatory syndrome in children (MIS-C). Mayo Clinic; 2020. Accessed Jan. 3, 2023.
  5. Information for healthcare providers about multisystem inflammatory syndrome in children (MIS-C). Centers for Disease Control and Prevention. https://www.cdc.gov/mis/mis-c/hcp/index.html. Accessed Jan. 3, 2023.
  6. Coronavirus disease 2019 (COVID-19): How to protect yourself & others. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html. Accessed Jan. 3, 2023.
  7. Son MBF, et al. Coronavirus disease 2019 (COVID-19): Multisystem inflammatory syndrome in children. https://www.uptodate.com/contents/search. Accessed Dec. 30, 2022.
  8. DeSimone DC (expert opinion). Mayo Clinic. Jan. 4, 2023.
  9. Multisystem inflammatory syndrome in children (MIS-C) interim guidance. American Academy of Pediatrics. https://services.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/clinical-guidance/multisystem-inflammatory-syndrome-in-children-mis-c-interim-guidance. Accessed Jan. 3, 2023.
  10. Aronoff SC, et al. The natural history of severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children (MIS-C): A systematic review. Journal of the Pediatric Infectious Diseases Society. 2020; doi:10.1093/jpids/piaa112.
  11. Ahmed M, et al. Multisystem inflammatory syndrome in children: A systematic review. EClinicalMedicine. 2020; doi:10.1016/j.eclinm.2020.100527.
  12. Feldstein LR, et al. Multisystem inflammatory syndrome in U.S. children and adolescents. The New England Journal of Medicine. 2020; doi:10.1056/NEJMoa2021680.
  13. Dufort EM, et al. Multisystem inflammatory syndrome in children in New York state. The New England Journal of Medicine. 2020; doi:10.1056/NEJMoa2021756.
  14. Case series of multisystem inflammatory syndrome in adults associated with SARS-CoV-1 infection — United Kingdom and United States, March-August 2020. MMWR Recommendations and Reports.2020; doi: 10.15585/mmwr.mm6940e1.
  15. Stay up to date. When you've been fully vaccinated. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html. Accessed Jan. 3, 2023.
  16. Melgar M, et al. Council of State and Territorial Epidemiologists/CDC surveillance case definition for multisystem inflammatory syndrome in children Associated with SARS-CoV-2 infection — United States. MMWR Recommendations and Reports. 2022; doi:dx.doi.org/10.15585/mmwr.rr7104a1.
  17. Multisystem inflammatory syndrome in adults (MIS-A). Centers for Disease Control and Prevention. https://www.cdc.gov/mis/mis-a.html. Accessed Dec. 30, 2022.

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Associated Procedures

Multisystem inflammatory syndrome in children (MIS-C) and COVID-19