Some children with MIS-C test negative for a current infection with the COVID-19 virus. This means they don't currently have the virus that causes COVID-19. Yet evidence indicates that many of these children were infected with the COVID-19 virus in the recent past, as shown by positive antibody test results.
An antibody test with a positive result means that the child's immune system developed blood proteins (antibodies) that fought the COVID-19 virus. Sometimes this blood test is the only indication that the child was ever infected — meaning that the child may have fought the infection without ever having signs or symptoms of COVID-19. Still, some children with MIS-C are currently infected with the virus that causes COVID-19. This is usually confirmed by detection of the virus on a swab taken from the back of the nose or throat.
In addition to doing antibody testing and a clinical assessment, doctors may order some of these tests to look for inflammation and other signs of MIS-C:
- Lab tests, such as blood and urine tests, including tests that look for an abnormal level of inflammatory markers in the blood
- Imaging tests, such as a chest X-ray, an echocardiogram, an abdominal ultrasound or a CT scan
- Other tests, depending on signs and symptoms
Inflammation can seriously affect the heart, blood vessels, kidneys, digestive system, brain, skin or eyes.
When doctors suspect MIS-C, they need to rule out active cases of COVID-19 as well as other inflammatory conditions such as Kawasaki disease, sepsis or toxic shock syndrome, for early diagnosis and proper treatment.
Most children with MIS-C need to be treated in a hospital. Some need treatment in a pediatric intensive care unit. Treatment usually involves supportive care and measures to reduce 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 (dehydration)
- Oxygen to help with breathing
- Blood pressure medications to normalize low blood pressure related to shock or to help with heart function
- A breathing machine (ventilator)
- Medications that reduce 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
- Other types of care
Treatment to reduce swelling and inflammation may include:
- Steroid therapy
- Intravenous immunoglobulin (IVIG), a blood product made up of antibodies
- Other types of treatment, such as targeted therapies aimed at reducing high levels of proteins called cytokines, which can cause inflammation
There is no evidence 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.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
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.
Do the best you can to take care of yourself by getting enough healthy food, sleep and physical activity. Try stress management techniques, such as deep breathing, stretching and meditation, to help you through these difficult times.
Preparing for your appointment
If your child shows any emergency warning signs of MIS-C or is severely sick with other signs and symptoms, 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. He or she may want to assess your child or refer you immediately to an infectious disease specialist.
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 medications, vitamins or other supplements your child takes, including the dosages
- Any group activities your child recently participated in, including the dates
- Questions to ask the doctor
What to expect from your doctor
vYour doctor is likely to ask you — and your child, depending on his or her 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 can help ensure that you have time to get all of your questions answered and learn what the next steps are and why they're important.