Diagnosis

Multisystem inflammatory syndrome in children (MIS-C) is diagnosed based on a child's symptoms and on ruling out other health issues.

MIS-C can look like other illnesses, such as:

  • Kawasaki disease.
  • Toxic shock syndrome.
  • Appendicitis.
  • Macrophage activation syndrome.
  • Severe COVID-19.

To test for COVID-19, your healthcare team may use a blood test or a swab of the nose or back of the throat. Or you may be asked about COVID-19 infections among a child's close contacts. Most kids who get MIS-C have had a link to the virus that causes COVID-19 within two months of getting sick.

To diagnose MIS-C, the healthcare team may use lab tests, such as blood and urine tests. Children also may have imaging tests, such as a chest X-ray, an echocardiogram, an abdominal ultrasound or a CT scan.

More Information

Treatment

Children with multisystem inflammatory syndrome are treated in a hospital. Some may need special care, for example, in a pediatric intensive care unit. Treatment depends on how sick the child is and which organs are affected.

Medicines used to treat MIS-C may include:

  • Antibiotics.
  • Steroids.
  • Intravenous immunoglobulin, a blood product made up of antibodies.
  • Medicines to lessen cytokines, which are proteins that cause inflammation.
  • Blood pressure medicines to treat low blood pressure related to shock or to help with heart function.
  • Medicines that lower the risk of blood clots, such as aspirin or heparin.

Supportive care may include:

  • Oxygen to make breathing easier.
  • A ventilator, to help a child breathe.
  • Extracorporeal membrane oxygenation (ECMO). With ECMO, a machine that does the work of the heart and lungs.

MIS-C isn't contagious. But there's a chance that your child could have COVID-19 or another type of contagious infection. So the care team uses infection control measures while caring for your child.

Coping and support

If your child has multisystem inflammatory syndrome, you may feel scared and anxious. Because MIS-C is rare, you may not know anyone who has gone through it. Talk with friends or family about how you feel. If you need more support, ask for help from a mental health professional. This person can help you manage your feelings.

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 room. 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 healthcare professional.

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 and other supplements your child takes, including the dosages.
  • Any group activities your child recently took part in, including the dates.
  • Questions to ask the healthcare professional.

What to expect from your doctor

Your healthcare 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.

June 02, 2026
  1. Multisystem inflammatory syndrome in children (MIS-C) Associated with SARS-CoV-2 Infection 2023 case definition. National Notifiable Diseases Surveillance System. https://ndc.services.cdc.gov/case-definitions/multisystem-inflammatory-syndrome-in-children-mis-c-2023/. Accessed Nov. 11, 2025.
  2. Son MBF. COVID-19: Multisystem inflammatory syndrome in children (MIS-C) clinical features, evaluation, and diagnosis. https://www.uptodate.com/contents/search. Accessed Nov. 7, 2025.
  3. Son MBF. COVID-19: Multisystem inflammatory syndrome in children (MIS-C) management and outcome. https://www.uptodate.com/contents/search. Accessed Nov. 7, 2025.
  4. Medical review (expert opinion). Mayo Clinic. Nov. 12, 2025.
  5. Jackson AK, et al. Hospitalizations for multisystem inflammatory syndrome in children (MIS-C) in US children's hospitals in 2023 vs 2021. JAMA Pediatrics. 2024; doi:10.1001/jamapediatrics.2024.2882.
  6. Spikevax (approval letter). Biologic License Application 125752. U.S. Food and Drug Administration. https://www.fda.gov/vaccines-blood-biologics/spikevax. Accessed Sept. 25, 2025.
  7. Mnexspike (approval letter). Biologic License Application 125835 U.S. Food and Drug Administration. https://www.fda.gov/vaccines-blood-biologics/mnexspike. Accessed Sept. 25, 2025.
  8. Comirnaty (approval letter). Biologic License Application 125742. U.S. Food and Drug Administration. https://www.fda.gov/vaccines-blood-biologics/comirnaty. Accessed Sept. 25, 2025.
  9. Nuvaxovid (approval letter). Biologic License Application 125817. U.S. Food and Drug Administration. https://www.fda.gov/vaccines-blood-biologics/vaccines/nuvaxovid. Accessed Sept. 25, 2025.
  10. Committee on Infectious Diseases. Recommendations for COVID-19 vaccines in infants, children, and adolescents: Policy statement. Pediatrics. 2025; doi:10.1542/peds.2025-073924.
  11. AskMayoExpert. COVID-19 vaccination. Mayo Clinic; 2025.
  12. Caliendo AM, et al. COVID:19: Diagnosis. https://www.uptodate.com/contents/search. Accessed Sept. 29, 2025.
  13. Smith B. COVID-19: Infection prevention for persons with SARS-CoV-2 infection. https://www.uptodate.com/contents/search. Accessed Sept. 5, 2025.
  14. Respiratory infections diseases: Mask use for reducing the spread. Public Health Agency of Canada. https://www.canada.ca/en/public-health/services/diseases/respiratory-infectious-diseases-reduce-spread-personal-protective-measures/masks.html. Accessed Sept. 5, 2025.
  15. Respiratory infectious diseases: How to reduce the spread with personal protective measures. Public Health Agency of Canada. https://workpermitcanada.us/en/public-health/services/diseases/prevent-spread-respiratory-viruses.html. Accessed Nov. 11, 2025.

Related

Associated Procedures

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