Multisystem inflammatory syndrome in children (MIS-C) is a serious condition that can develop after a COVID-19 infection. It causes inflammation in multiple organs and systems of the body.

mother taking her child's temperature in bed checking for MIS-CShare on Pinterest
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Multisystem inflammatory syndrome in children (MIS-C) is rare. It’s an inflammatory condition that affects some children following a COVID-19 infection.

There are treatment options available, and prompt treatment can make a huge difference. That’s why it’s so important to be able to recognize the symptoms of MIS-C so that you know when it’s time to contact a healthcare professional and seek care.

Most children who have MIS-C need specialized hospital care, including ICU treatment and continued follow-up care. The sooner a child receives this care, the better.

The symptoms of MIS-C can vary. The condition is characterized by widespread inflammation in the body and can affect more than one organ. Symptoms usually develop about 2-8 weeks after a COVID-19 infection.

Symptoms are similar to toxic shock syndrome or Kawasaki disease, with many children experiencing symptoms of shock. Usually, children with MIS-C experience a fever, along with inflammation and symptoms in one or more of the following organs:

Eyes

Red eyes or bloodshot eyes are associated with MIS-C. One study from 2022 found that about 52% of children with MIS-C presented with conjunctivitis.

Skin and mucous membranes

Most children with MIS-C have mucocutaneous symptoms, or symptoms of the skin and mucous membranes. These symptoms may include:

  • red rash with bumps, blotches, or spots.
  • swollen palms of hands and feet.
  • swollen, discolored lips.
  • swollen, bumpy tongue (strawberry tongue)
  • redness across cheeks and bridge of the nose
  • blue, gray, or pale skin, lips, and nail beds

Heart

Researchers have found that up to 80% of children with MIS-C may have potentially serious cardiac conditions, including:

  • Myocarditis: Myocarditis is inflammation of the heart muscle.
  • Coronary artery aneurysms: Coronary artery aneurysms occur when one or more artery near the heart becomes enlarged.
  • Conduction abnormalities: Also called heart block, conduction abnormalities are interruptions in the electrical signals in your heart.
  • Arrhythmia: An arrhythmia is an irregular heart rate.

Neurological symptoms

MIS-C can affect the brain and nerves. It has been linked with changes in the brain that can affect cognitive function. It can cause signs of meningitis, including headaches and seizures.

Gastrointestinal system

People with MIS-C often experience stomach pain, diarrhea, and vomiting.

Kidneys

MIS-C has been associated with acute kidney injury, especially among children who are critically ill.

When is MIS-C an emergency?

If your child has symptoms of MIS-C, contact your child’s doctor or healthcare professional immediately.

Certain symptoms require emergency medical care, including:

  • shortness of breath
  • disorientation
  • extreme fatigue
  • chest pressure
  • blue or gray lips or fingernails
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MIS-C is a serious inflammatory condition that occurs several weeks after a COVID-19 infection. It was first noted in children, but it was later discovered that it can affect adults as well, though it’s more common in children.

MIS-C may include inflammation that can affect multiple organs in the body, such as the skin, heart, brain, and digestive system.

Children with MIS-C almost always need hospital care, and many will spend time in the Pediatric ICU (PICU). Often, specialists, like pediatric cardiologists or pediatric rheumatologists, will be called in to help manage symptoms.

In children, treatment options may include:

  • medications that help manage immune reactions and inflammation
  • intravenous immunoglobulin
  • steroids
  • medications that reduce the chances of blood clots

Experts are not completely sure what causes MIS-C. The condition is associated with a COVID-19 infection, either confirmed with a diagnostic test or an antibody test. Many have suspected that the condition is associated with a delayed overreaction of the immune system.

Most children who have MIS-C don’t have any other medical conditions; however, among children with MIS-C who do have an underlying condition, obesity is the most common.

The Centers for Disease Control and Prevention (CDC) recommends COVID-19 vaccines for all children ages 6 months and older and boosters for all children ages 5 years and older if eligible.

The three vaccines approved for use in children in the United States include:

  • Pfizer-BioNTech for children 6 months to 17 years
  • Moderna for children 6 months to 17 years
  • Novavax for children 12 and older

COVID-19 vaccination may help protect a child against severe disease and hospitalization from COVID-19.

MIS-C is diagnosed based on clinical symptoms, a child’s medical history, as well as diagnostic test results. Your child’s doctor may ask about past COVID-19 infections or perform a COVID-19 detection or antibody test. They’ll also take your child’s vital signs, including temperature, heart rate, and blood pressure.

Your healthcare team will note what symptoms of MIS-C your child has, including:

  • stomach pain
  • skin rash
  • bloodshot eyes
  • fever
  • vomiting
  • diarrhea
  • extreme lethargy
  • dizziness

In addition, your provider may perform certain tests to understand what is happening in your child’s body. Tests may include:

MIS-C is rare, and most children recover if they receive proper treatment in the hospital. However, some children have died as a result of MIS-C, and many experience symptoms that last for months or weeks after acute symptoms have resolved.

Most children have no major health issues a year after being diagnosed with MIS-C, according to the CDC. However, even after receiving hospital care, children will need follow-up care to ensure their hearts and other major organs are recovering fully. Most organ-related issues in children resolve in 6 months.

MIS-C is a serious condition that can affect children after a COVID-19 infection. Experts are still learning what causes it and what the long-term effects of experiencing it may be.

Understanding the symptoms of MIS-C is important because getting prompt treatment for the condition is vital. If your child has symptoms, contact your child’s doctor or a healthcare professional as soon as possible.