by Scholten A


Multisystem inflammatory syndrome A (MIS-A) is a rare condition. It is linked to COVID-19. It leads to inflammation in the body. The digestive system, heart, brain, or other organs may be affected. It can be life-threatening.


MIS-A usually develops after a COVID-19 infection. The exact cause is not clear. It may be due to an overreaction of the immune system.

Risk Factors

MIS-A affects people 21 years old or older. The main risk for MIS-A is a recent COVID-19 infection. It can happen even if the COVID-19 infection has no symptoms.


Symptoms of MIS-A develop days to weeks after getting COVID-19. They may be:

  • Fever and chills
  • Pain in the belly, chest, or neck
  • Eye redness
  • Loose stools (poop)
  • Being very tired
  • Headache, dizziness, or lightheadedness
  • Rash
  • Vomiting

Severe symptoms need care right away. They include:

  • Problems breathing
  • Lasting chest pain
  • Problems thinking or staying awake
  • Pale gray or blue color to skin, lips, or nails


The doctor will ask about symptoms and past health. A physical exam will be done.

Tests will be done to look for inflammation and organ damage. They may include:

  • Blood tests
  • Images such as:
    • Chest x-rays—to check the lungs
    • Abdominal ultrasound—to look at organs in the belly area
    • Echocardiogram—to check the heart

Other tests may also be done.

Diagnosis is based on recent COVID-19 infection, symptoms, and test results.


Treatment of MIS-A depends on how severe the symptoms are. It also depends on the affected body part. The goals are to reduce inflammation and prevent organ damage.

Supportive care may be given in the hospital. It may include:

  • Oxygen—to help breathing
  • Fluids—to prevent dehydration
  • A breathing machine

Medicines may be given, such as:

  • IV immunoglobulin—proteins to help fight infection
  • Corticosteroids—to lower inflammation
  • Antibiotics—to prevent or treat infections
  • Low dose aspirin—to prevent blood clots
  • Blood pressure medicines
  • Other medicines to decrease proteins that cause inflammation

Many recover. For some, the condition is fatal or causes lasting organ damage.


To reduce the risk of MIS-A, take steps to help prevent COVID-19 infection. This includes:

  • Getting the recommended number of COVID-19 vaccine doses, if eligible
  • Wearing a face mask in indoor public areas
  • Practicing social distancing


Centers for Disease Control and Prevention 

National Institutes of Health 


Health Canada  

Infection Prevention and Control Canada  


COVID-19 (Novel Coronavirus). EBSCO DynaMed website. Available at: Accessed September 3, 2021.

Multisystem inflammatory syndrome. Centers for Disease Control and Prevention website. Available at: Accessed September 3, 2021.

Multisystem inflammatory syndrome in adults (MIS-A). Centers for Disease Control and Prevention website. Available at: Accessed September 3, 2021.

Tenforde MW, Morris SB. Multisystem inflammatory syndrome in adults: coming into focus. Chest. 2021;159(2):471-472.

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