Early this year, as people across the world became aware of and took precautions against COVID-19, the serious—sometimes fatal—disease associated with the SARS-CoV-2 coronavirus, many took a small measure of comfort in believing that children infected with the disease were left relatively unharmed.
But in late April, physicians in Europe and the United States began to report a small but growing number of cases of children afflicted with a new multisystem inflammatory syndrome that appears to be associated with COVID-19. Doctors began to report seeing very sick children, many of whom tested positive for COVID-19, with some combination of fever, red eyes, swollen hands and feet, rash, and gastrointestinal problems, all of which are symptoms related to inflammation.
At first, doctors noted similarities between these symptoms and those associated with other inflammatory syndromes, such as Kawasaki disease and toxic shock syndrome. But as they began to see more of these children, they started to suspect they were seeing something different. The condition was first called PMIS (pediatric multisystem inflammatory syndrome) but is now officially known as multisystem inflammatory syndrome in children, or MIS-C.
Because MIS-C has only recently been identified, the medical community is still trying to understand what causes it, as well as why it appears to affect only children. And while there is mounting evidence that it is linked to COVID-19, the relationship between the two is not yet known. What is clear is that MIS-C is a serious health issue that requires prompt medical attention. Fortunately, it is also rare, and the vast majority of children affected by it survive.
“This new entity seen in children is a severe post-infectious manifestation of the virus,” says Marietta Vázquez, MD, a Yale Medicine pediatric infectious disease specialist. “It calls for us to be vigilant to its presentation without panic, as it remains rare.”