While the number of COVID-19 cases across the country is decreasing, pediatricians at Monroe Carell Jr. Children's Hospital at Vanderbilt are beginning to see a new post-surge trend: an increase in cases of multi-system inflammatory syndrome in children (MIS-C).
The cause of the rare illness is unknown but is believed to be connected to COVID-19, appearing about four weeks after a COVID-19 infection or exposure. In children with MIS-C, different parts of the body can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes or gastrointestinal organs.
Children's Hospital has treated approximately 30 children for MIS-C since mid-July 2020, with 10 of those in the last month.
Tennessee has seen more than 51 cases of MIS-C, according to Centers for Disease Control and Prevention (CDC) data. Meanwhile, the state has had more than 126,977 cases of COVID-19 among patients 20 years and younger, according to a recent American Academy of Pediatrics report.
"Although MIS-C can be serious, it's still relatively rare," said Sophie Katz, MD, MPH, assistant professor of Pediatric Infectious Diseases at Children's Hospital. "We're seeing more of it because of an increase in COVID-19 cases in the community, and the fact that MIS-C occurs four-plus weeks after COVID-19 exposure. It does sometimes occur in children who don't know they were exposed to COVID-19, but about 90% of children who develop MIS-C do know that they were exposed to COVID-19."
Experts at Children's Hospital are advising parents on what symptoms to look for, especially in children who have or have had COVID-19. MIS-C can be serious and life-threatening, but if caught early can be successfully treated. It is not contagious.
MIS-C symptoms include:
- Fever
- Abdominal pain
- Vomiting
- Diarrhea
- Neck pain
- Rash
- Changes inside the mouth, i.e. red tongue
- Bloodshot eyes
- Swelling of hands and feet
- Feeling extra tired
"MIS-C can affect the heart, and that's why we take it so seriously. Parents should call their doctor if they develop these symptoms. More severe symptoms requiring emergency care include trouble breathing, pain or pressure in the chest that doesn't go away, new confusion or difficulty waking or staying awake," Katz said. "Of the children who have been seen in our outpatient MIS-C clinic, all are back to their baseline health by one month after hospital discharge."
While serious, MIS-C is extremely uncommon. As of Feb. 5, the CDC website reported 1,659 confirmed cases of MIS-C and 26 deaths in 47 states, New York City and Washington, D.C. The average age of these inflammatory cases is in children between ages 1 and 14. The disease also has disproportionately impacted Black and Hispanic communities, with 70% of MIS-C cases affecting these demographic groups.
Doctors don't know why some children develop MIS-C while others don't, but there are research studies being conducted throughout the country to gain insight into the syndrome. They stress that the best way to prevent MIS-C is to prevent COVID-19 infection in the first place.
"A small proportion (about 20%) will shed COVID-19 while they have MIS-C. As people go back to school, maintaining the usual strategies to prevent COVID-19 exposure will be important - wear your mask, wash your hands, and try not to be within three to six feet of other people," Katz said.