Also called: Pediatric Multisystem Inflammatory Syndrome (PMIS); Pediatric Inflammatory Multisystem Syndrome (PIMS)

What Is Multisystem Inflammatory Syndrome in Children (MIS-C)?

COVID-19 seems to usually cause a milder infection in kids than in adults and older people. But some children have developed more serious symptoms, sometimes several weeks after being infected with the virus. This condition is called multisystem inflammatorysyndrome in children (MIS-C). Experts are still studying how these symptoms are related to COVID-19 and why they happen in some children and not others.

What Are the Signs of Multisystem Inflammatory Syndrome in Children (MIS-C)?

MIS-C causes symptoms that are due to inflammation (irritation, pain, swelling) throughout the body:

• a fever
• belly pain
• vomiting or diarrhea
• a rash
• red, cracked lips
  
• red eyes
• being extra tired
• swollen hands or feet
• swollen lymph nodes

If your child has ongoing fever and more than one of these symptoms, call your doctor. Kids with this inflammatory syndrome may quickly get worse. Go to the ER right away if your child looks very sick, has trouble breathing, has chest pain, has very bad belly pain, looks bluish in the lips or face, or is very sleepy or confused. Tell the doctor if your child has had COVID-19 or has been exposed to someone who had it.

What Problems Can Happen?

MIS-C can cause different problems in different kids. The inflammation can affect the heart, lungs, blood vessels, kidneys, skin, digestive system, brain, or eyes. Sometimes, this can damage the organs, especially the heart, or cause too much clotting in the blood vessels.

How Is MIS-C Diagnosed?

MIS-C symptoms can be similar to those caused by other illnesses, such as Kawasaki disease or toxic shock syndrome. If a doctor thinks a child might have MIS-C, they will do a COVID-19 test and other tests that look for signs of inflammation in the body. These can include:

• blood tests and urine (pee) tests
  
• chest X-ray
  
• tests to look at the heart, such as ECG (electrocardiogram) and echocardiogram (ultrasound of the heart)
• abdominal ultrasound

The doctor might talk with a team of specialists who can help diagnose and treat MIS-C. They can include experts in infectious disease, cardiology (heart), rheumatology (bones, joints, and immune system), and critical care.

How Is MIS-C Treated?

How doctors treat MIS-C depends on a child's symptoms and test results. They can give oxygen, medicines, and intravenous (IV) fluids to reduce inflammation, prevent excessive blood clotting, or protect the affected organs from more problems. Some children might need treatment in the ICU (intensive care unit).

What Else Should I Know?

Most kids with MIS-C get better after being treated in the hospital. But some can have lasting problems and need care from specialists after they go home.

For example, kids who develop heart problems due to MIS-C will need regular visits with a cardiologist. They may have to avoid exercise or sports for a while, until the cardiologist says it's OK. Kids who get some kinds medicines (like steroids for easing inflammation) will see a specialist, such as a rheumatologist or endocrinologist, who can help them adjust their medicines as needed.

MIS-C is very rare. The best way to prevent it is to prevent COVID-19. Everyone 6 months of age or older should get an updated COVID-19 vaccine this 2023–24 season. The updated vaccine protects against the variants that are now most common.

To help prevent the spread of germs, it’s always a good idea to:

• Wash hands well and often. Wash for at least 20 seconds with soap and water or use hand sanitizer with at least 60% alcohol.
  
• Avoid people who appear sick.
• Clean things that get touched a lot (like doorknobs, counters, phones, etc.).