Multisystem Inflammatory Syndrome in Children (MIS-C) and COVID-19 – Symptoms and Causes

ByJanis Updated

Overview

Multisystem inflammatory syndrome in adults (MIS-A) is a rare but serious condition where multiple body systems become inflamed following COVID-19 infection. MIS-A emerged during the COVID-19 pandemic, with the first cases identified in 2020.

Adults with MIS-A typically develop symptoms within 2 months after having COVID-19. However, some patients may not have experienced severe or noticeable COVID-19 symptoms during their initial infection.

The condition involves inflammation affecting various organs, including blood vessels, the heart, the digestive system, the skin, and the eyes.

Key characteristics of MIS-A:

  • Occurs rarely in adults
  • Appears after COVID-19 infection (even mild cases)
  • Requires hospitalization
  • Can become life-threatening if not treated promptly

Medical experts continue to research the exact causes and risk factors for MIS-A. The condition represents a serious inflammatory response that differs from acute COVID-19 symptoms.

While most adults recover with appropriate medical treatment, the condition can progress rapidly in some cases.

Signs and Symptoms

Multisystem inflammatory syndrome in children (MIS-C) shows serious symptoms that require hospital treatment. Each child may experience different symptoms. Doctors may diagnose MIS-C when a child:

  • Has had COVID-19 or was exposed to someone with COVID-19 within 2 months of hospitalization
  • Shows fever
  • Has blood tests indicating widespread inflammation in the body

Additionally, the child must have at least two of these symptoms:

  • Heart complications
  • Red, bloodshot eyes
  • Swollen or red lips and tongue
  • Redness or swelling in hands or feet
  • Stomach pain, vomiting, or diarrhea
  • Blood clotting issues
  • Shock

Seek emergency care immediately if your child develops:

Warning SignWhat to Look For
Severe abdominal painIntense stomach pain that causes distress
Chest discomfortPressure or pain in the chest area
Breathing difficultiesShortness of breath or labored breathing
DiscolorationGray or bluish skin, lips, or nail beds
Mental changesNew confusion or disorientation
Alertness problemsCannot wake up or stay awake

For less severe symptoms that match MIS-C, contact your child’s doctor right away for guidance. The medical team may recommend tests to check for inflammation and other MIS-C indicators, including blood tests and imaging of the chest, heart, or abdomen.

Causes

The exact cause of MIS-C remains unknown. Many children who develop this condition have recently been infected with COVID-19, while others may have an active infection when symptoms appear.

Researchers believe that the immune system’s response to the COVID-19 virus might play a key role. One theory suggests that MIS-C occurs when the body’s immune system overreacts to the virus, either during or after infection.

This immune overreaction can trigger inflammation throughout the body, affecting multiple organs and systems.

Risk Factors

Children aged 5 to 11 years old are most commonly diagnosed with MIS-C. However, cases have been reported in children from 1 to 15 years of age. In rare instances, MIS-C affects older teenagers and infants as well.

Complications

MIS-C can cause serious problems if not found and treated early. The condition affects important organs, especially the heart. Some children with MIS-C may face lasting organ damage. In the worst cases, this condition can be fatal.

Preventing COVID-19

COVID-19 vaccines provide significant protection against the virus for everyone aged 6 months and older.

Getting vaccinated helps prevent infection and reduces the risk of serious illness if you do contract the virus. Vaccines also help reduce transmission to others around you.

Beyond vaccination, several everyday practices can significantly reduce your risk of catching or spreading COVID-19:

Hand Hygiene Practices:

  • Wash hands thoroughly with soap and water for at least 20 seconds.
  • Use hand sanitizer with at least 60% alcohol when soap isn’t available.

Social Distancing Measures:

  • Stay away from people showing symptoms like coughing or sneezing.
  • Maintain distance from others in public indoor spaces. This is especially important in poorly ventilated areas.
  • Wear well-fitting face masks in public indoor settings when community COVID-19 levels are high.

Respiratory Hygiene:

  • Avoid touching your face, particularly your eyes, nose, and mouth.
  • Cover coughs and sneezes with tissues or your elbow.
  • Dispose of tissues properly after use.
  • Wash hands immediately after coughing or sneezing.

Environmental Cleaning:

  • Regularly disinfect frequently-touched surfaces in your home.
  • Focus on items like doorknobs, light switches, remote controls, and keyboards.

Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.