Study Explores Which Kids Are Most At Risk For MIS-C

Mother putting a mask on her child.

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Key Takeaways

  • A rare but severe medical condition associated with COVID-19 called multisystem inflammatory syndrome in children (MIS-C) has been observed in individuals up to 21 years of age, and significantly more frequently in racial minorities.
  • A study shows that most MIS-C cases resulted from asymptomatic or mild COVID-19 infection.
  • If you suspect that your child has MIS-C, it’s important to seek medical attention right away to get treated and avoid lasting damage.
  • The best way to keep children from developing MIS-C is to prevent COVID-19 exposure and infection, experts say.

Compared to adults, fewer children and teens have gotten severely sick from COVID-19, and most of them experienced mild to no symptoms. However, the Centers for Disease and Control and Prevention (CDC) has identified a rare medical condition associated with COVID-19 called multisystem inflammatory syndrome in children (MIS-C). And a new study shows its seems to be disproportionately affecting racial minorities.

MIS-C causes severe inflammation in many vital organs such as the heart, lungs, kidneys, brain, and more.

The study, published in JAMA Pediatrics earlier this month, shows MIS-C affected more Hispanic and Black children and adolescents between March 2020 and January 2021 (71.3% of the 1,733 pediatric patients involved) than White children and adolescents.

“We currently do not know why Hispanic and Black children seem to be at higher risk for MIS-C, but it is an observation that has been consistently seen," Christine Elizabeth Mikesell, MD, clinical assistant professor of pediatrics at Michigan Medicine C.S. Mott Children’s Hospital, tells Verywell. "Studies are starting to look at this relationship, hopefully, we will have more information in the future."

This disparity might be reflecting the proportion of children who have been infected with SARS-CoV-2 since communities of color have had high rates of COVID-19.

“I think the increased risk of MIS-C really reflects the increased risk of getting infected in the first place,” Audrey R. Odom John, MD, PhD, chief of the Division of Pediatric Infectious Diseases at Children's Hospital of Philadelphia, tells Verywell. “While I expect we will ultimately identify genetic differences in children who get MIS-C from SARS-CoV-2 compared to children who do not, I am not convinced that the racial imbalance reflects biological differences, as much as it reflects health disparities.”

The Association Between MIS-C and COVID-19

According to the JAMA Pediatrics study, the emergence of MIS-C is likely due to delayed immunologic responses to SARS-Cov-2, the virus that causes COVID-19. Most cases of MIS-C appear to result from asymptomatic or mild COVID-19 infection. The CDC also states that many children with MIS-C have had, or been around someone with, COVID-19.

“Many times, parents know that someone in the household has had COVID-19—and, in fact, often multiple household members," John says. "But because the child never had any symptoms, they don’t get tested. It is important to know that MIS-C can come from asymptomatic infections because parents should be on the lookout for MIS-C if their child has had a significant COVID-19 exposure, even if they never seemed to get COVID themselves.”

Symptoms of MIS-C

Although MIS-C is potentially life-threatening, keep in mind that it is both rare and treatable.

“It is quite rare—perhaps less than 1 in 10,000 or 1 in 100,000 coronavirus infections—but can be serious," John says. "So parents should not be too worried, but equally should not hesitate to bring their child to care if they have persistent fever."

Knowing the signs to watch out for in children can help parents seek medical care immediately and avoid lasting organ damage. According to the CDC, parents should look out for these symptoms of MIS-C:

  • Abdominal pain
  • Diarrhea
  • Rash
  • Vomiting
  • Bloodshot eyes
  • Fever
  • Neck pain
  • Extreme fatigue

"While every patient is different, we have seen that younger kids tend to present with a constellation of symptoms similar to those of Kawasaki Disease (KD)," Mikesell says. "They have fever, rash, and conjunctivitis. Older children and teenagers are more likely to have gastroenteritis symptoms such as fever, abdominal pain, nausea, vomiting, and diarrhea."

However, symptoms still vary and not all children will exhibit the same symptoms every time.

What This Means For You

If your child is exhibiting symptoms of COVID-19 or MIS-C, it's important to seek emergency care right away by calling 911 or going to your local emergency facility. Watch out for emergency warning signs such as breathing difficulties, chest pain or pressure, severe abdominal pain, and/or pale, gray, or blue-colored skin, lips, or nails.

How MIS-C Compares to Kawasaki Disease

Initially, medical experts found that the clinical symptoms of MIS-C are similar to that of toxic shock syndrome and KD.

According to John, MIS-C symptoms like fever, rash, and conjunctivitis also occur with KD, but toxic shock is less common. “Most experts in this area now believe that KD and MIS-C are different, but they are still difficult to distinguish although there are some notable differences in laboratory values [from] blood tests," she adds.

While coronary artery aneurysms may develop in KD, they occur less frequently in MIS-C, and patients commonly experience cardiac dysfunction. The age range for both health conditions notably differs, too. KD commonly affects children below 5 years old, but MIS-C can affect adolescents up to 21 years of age.

“While we have long suspected that Kawasaki Disease is a post-virus inflammatory condition, we have not been able to tease out which virus(es) is responsible or a potential timeline," Mikesell says. "We can clearly see the pattern that MIS-C follows a COVID-19 infection."

How to Prevent MIS-C

Experts say that the best way to protect your child from developing MIS-C is to prevent COVID-19 exposure and infection in the first place. Mask-wearing and physical distancing are still important safety precautions to practice, and households of mixed vaccinated status are generally not recommended to convene.

“Adults above 16 years should absolutely get vaccinated as soon as COVID-19 vaccines are made available to them, as many children appear to become infected from the adults they live with,” John says.

As of April 19, President Joe Biden made all American adults eligible for the COVID-19 vaccine. The availability of COVID-19 vaccines for kids will be beneficial in preventing both COVID-19 and MIS-C when the time comes.

Currently, all three vaccine companies have clinical trials underway for children. Last March, Pfizer announced that their COVID-19 vaccine had 100% efficacy in adolescents aged 12 to 15 years old. They already requested the Food and Drug Administration (FDA) to amend their emergency use authorization (EUA) to individuals 12 and up. Moderna has yet to release the results of their vaccine clinical trials in children aged 12 to 17. And both companies have begun their clinical trials to test vaccine efficacy in children aged 6 months to 11 years old. Johnson & Johnson shared in its application for emergency use authorization that the company plans to study its vaccine in children aged 12 to 17, followed by newborns.

“If your child develops a fever and other symptoms, you should discuss with your doctor sooner than you usually would, even if your child has not had a recent known COVID-19 infection,” Mikesell says. “[The] lack of a known COVID-19 infection doesn't mean you can not have MIS-C. If a child has a fever or concerning symptoms, they should be evaluated for potential MIS-C.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Belay ED, Abrams J, Oster ME, et al. Trends in geographic and temporal distribution of US children with multisystem inflammatory syndrome during the COVID-19 pandemic. JAMA Pediatr. doi:10.1001/jamapediatrics.2021.0630

  3. Centers for Disease Control and Prevention. Multisystem inflammatory syndrome (MIS-C).

  4. Centers for Disease Control and Prevention. For parents: multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19.

  5. Saguil A, Fargo M, Grogan S. Diagnosis and management of Kawasaki disease. Am Fam Physician. 2015 Mar 15;91(6):365-71. PMID: 25822554

  6. Friedman KG, Harrild DM, Newburger JW. Cardiac dysfunction in multisystem inflammatory syndrome in children: a call to action. J Am Coll Cardiol. 2020;76(17):1962-1964. doi:10.1016/j.jacc.2020.09.002

  7. Stanford Children's Health. Kawasaki disease in children.

  8. Centers for Disease Control and Prevention. Information for healthcare providers about multisystem inflammatory syndrome in children (MIS-C).

  9. Pfizer. Pfizer-BioNTech announce positive topline results of pivotal COVID-19 vaccine study in adolescents.

  10. Food and Drug Administration. Vaccines and Related Biological Products Advisory Committee meeting.

By Carla Delgado
Carla M. Delgado is a health and culture writer based in the Philippines.