COVID-19 Resource Center

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Healio Interview

Disclosures: Thacker reports no relevant financial disclosures.
March 10, 2021
4 min read

Q&A: Inflammatory response to COVID-19 infection in children may affect CV, other systems


Healio Interview

Disclosures: Thacker reports no relevant financial disclosures.
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Hospitals in the U.S. and the CDC have reported rising incidence of multisystem inflammatory syndrome in children after COVID-19 infection.

According to the CDC, multisystem inflammatory syndrome in children (MIS-C) is a condition in which organ and systems such as the heart, lungs, kidneys, brain, skin, eyes or gastrointestinal organs can become inflamed.

Graphical depiction of source quote presented in the article
Deepika Thacker, MD, pediatric cardiologist at the Nemours/Alfred I. duPont Hospital for Children in Wilmington, Delaware.

Healio spoke with Deepika Thacker, MD, pediatric cardiologist at the Nemours/Alfred I. duPont Hospital for Children in Wilmington, Delaware, about the rising incidence of MIS-C and what clinicians and parents need to look out for.

Healio: What is the prevalence of MIS-C within this patient population?

Thacker: MIS-C is still quite rare. The CDC updates its website regularly with ongoing data from the mandatory reporting from all states. As of Feb. 8, the CDC was reporting a total of 2,060 cases across the country. The number may be lagging because, even at Nemours, it takes us a few weeks to get all the data they require out. You will see a higher number when we do the final tally.

Prevalence of MIS-C is not incredibly high when considering that about 3.1 million U.S. children have been diagnosed with COVID-19.

Healio: What is the underlying mechanism behind MIS-C in children with COVID-19?

Thacker: The immune system of children responds differently to different viruses and bacteria. There are some other conditions that follow a similar pattern in children. One of them, Kawasaki disease, is a condition in which there is inflammation of the coronary arteries, and is seen typically in children younger than 5 years.

There is another condition that has been around for much longer called rheumatic fever, which is caused by the body’s immune response attacking its own tissues after a streptococcal infection. The streptococcus shares some antigens with the body and the immune response of the body, then starts attacking the cells of the person’s body itself, like the heart, joints and skin. In COVID-19, there is probably a similar mechanism. The body is trying to mount an immune response to a foreign virus and, in the process, it starts attacking some of the host’s own tissue, resulting in this syndrome.

Healio: Is there any trend among patients with COVID-19 as far as which systems are attacked?

Thacker: Yes, there are many. The pattern is somewhat different from what we have seen in the other conditions I mentioned. One of the most common systems being attacked is the gastrointestinal system. A lot of these kids are presenting with abdominal pain, vomiting and diarrhea. Some of them are presenting with features that very closely mimic appendicitis. One of our children presented after getting an appendectomy at an outside hospital, and after the surgery, they realized the appendix was normal and the child continued to deteriorate clinically. They transported the child to us for further management. The child was diagnosed and treated for MIS-C and did well.

The other organ that is involved, and the one that is most concerning, is the heart. More than half of these children with MIS-C have involvement of the heart. The heart function may be affected, and coronary arteries may be slightly enlarged.

Other features that we commonly see are less concerning such as conjunctivitis. The eyes and mouth can appear red; there can be a rash on the body; some children present with irritability and headaches; and a smaller number present with kidney dysfunction. A couple of our children have required management to support the kidney function but have recovered.

Healio: Are there any common risk factors among these children?

Thacker: From data across the country, which is mirroring what we are seeing as well, almost 60% to 70% of these children are from ethnic minorities: the Hispanic and non-Hispanic Black populations. The more severe MIS-C cases that we have seen at Nemours have been in children older than 10 years; however, we have seen the condition in all ages. Our youngest patients were 4 months old and our oldest, so far, was 18 years. MIS-C was also more severe among boys compared with girls.

Healio: What is your institution doing to care for these patients?

Thacker: We identified our first case of COVID-19-related MIS-C in April 2020, before it was reported by CDC or by other centers across the country. We came together with specialists from different departments such as rheumatology, infectious diseases, ICU, cardiology and ED and we put together management protocols. We created order sets and educational sessions for our staff. We are focusing on educating other clinicians as well as the community. We have a huge outreach effort to educate not only pediatricians, but also parents, about COVID-19-related MIS-C, and we are heavily involved in research as to why it happens, who it happens in and what we can do to prevent it. We have figured out best practices to manage MIS-C, all our children have done well, and we have outpatient follow-up arranged for them.

Healio: Should other hospital systems increase screening for COVID-19-related MIS-C?

Thacker: I believe they already have. In the Delaware Valley, we have done talks, presented grand rounds and communicated with other institutions, and they are increasing their screening efforts. Pediatricians are now aware, and we’ve done a lot of outreach, but we need to create more awareness in the general public because this is a condition that usually occurs 2 to 6 weeks out from initial COVID-19 infection. It is not usually part of the initial diagnosis. A lot of our children are asymptomatic or have mild COVID-19 infection. Some did not know they had COVID-19, but their family members were exposed, and 4 weeks later, the child presented with symptoms of MIS-C.

Ongoing vigilance on the part of the family is important, especially in that window. If a child is diagnosed with COVID-19, then 2 to 6 weeks out, any fever should be taken more seriously, especially if there is a rash, conjunctivitis or any abdominal symptoms. At that point, they should seek out a visit with their pediatrician.

Healio: Is there anything else that you would like to add?

Thacker: The best way to prevent MIS-C or complications from MIS-C is to prevent COVID-19. Emphasis comes back to masking, social distancing, hand hygiene and quarantining when it is appropriate, either for someone who has COVID-19 or is in close contact. When the vaccines are available, get vaccinated. I know we do not have any for children, but if we can protect the adults in the community, the children are less likely to get it, which would prevent MIS-C as well.


For more information:

Deepika Thacker, MD, can be reached at