Three more children in Los Angeles County have been diagnosed with a rare and potentially deadly inflammatory syndrome believe to be linked to COVID-19, officials said Friday.

A total of 28 children are now confirmed to have multisystem inflammatory syndrome, or MIS-C, since the pandemic began, according to the L.A. County Department of Public Health.

The condition affects some who have been exposed to COVID-19, causing inflammation in various body parts including heart, lungs, kidneys, brain, skin, eyes and gastrointestinal organs. It can carry lifelong health impacts, health officials say.

While the illness is serious and can lead to death, it has yet to be linked to any child fatalities in L.A. County.

Parents should contact a doctor immediately if their child shows symptoms of MIS-C, which can include fever, abdominal pain, vomiting, diarrhea, neck pain, rash, bloodshot eyes and fatigue, according to the U.S. Centers for Disease Control and Prevention.

Most patients develop the sickness within a month of being infected with the coronavirus, the CDC says.

The CDC is still learning about the syndrome, and it’s unclear why some children are sickened and others aren’t.

As of Aug. 20, the agency had confirmed 694 cases of the inflammatory syndrome and 11 deaths across 42 states.

In L.A. County, the majority of those diagnosed with MIS-C — 71% of patients — are Latino. The ethnic group has also been disproportionately impacted by COVID-19.

County health officials say 28% of those who it has identified with the illness are 5 years old or younger, 39% are between 6 and 12, and 32% are 13 to 20 years old.