PARK RIDGE, Ill. (WGN) — A Chicago area doctor is warning parents about a rare COVID-19 complication that threatens children.

First identified in Europe and later in New York, it now appears the mysterious ailment – pediatric multisystem inflammatory syndrome – may have reached other parts of the United States.

Dr. Frank Belmonte with Advocate Children’s Hospital told sister station WGN that doctors are working with a young patient at Advocate Children’s Hospital who appears to be suffering from this mysterious syndrome. No details were available on the child’s condition.

“Basically, these kids probably have been exposed to COVID in the recent four-to-six week period, have convalesced from that, and now are having this inflammatory viral response,” he said. “Many of them are not testing positive through a nasal swab, but we’re actually finding antibodies in their blood that are consistent with a past exposure to the COVID virus.”

Belmonte said the illness presents with symptoms similar to Kawasaki disease or toxic shock syndrome. Those symptoms include fever, abdominal pain, diarrhea, vomiting and rash.

“This is a rare occurrence, but we’re seeing now, across the world, that this is happening,” Belmonte said. “So our real goal here is to educate parents that if they see those symptoms I’ve mentioned, as well as educate their pediatricians if they are alerted to these things.”