Riverside County officials on Tuesday reported the first child case of a potentially deadly inflammatory syndrome that has been linked to the coronavirus.

The patient diagnosed with multisystem inflammatory syndrome in children, or MIS-C, is under 15 years old and lives in western Riverside County, according to Riverside University Health System-Public Health.

Officials said they’re also investigating a second probable case in the Coachella Valley. No death linked to MIS-C has been reported in the county.

Some children develop MIS-C after falling ill with COVID-19 or being in contact with someone with the coronavirus, according to the U.S. Centers for Disease and Control and Prevention.

The heart, lungs, kidneys, brain, skin, eyes or gastrointestinal organs of an MIS-C patient may become inflamed. Symptoms include gut pain, vomiting, diarrhea, neck pain, rashes, bloodshot eyes and fatigue, the CDC said.

While the disease is rare, the U.S. has confirmed 11 MIS-C deaths and 694 cases across 42 states and Washington D.C. since May, according to the CDC. The average patient age is 8 years old, and more than 70% of cases have been diagnosed in Hispanic or Black children, officials said.

In California, health authorities have reported at least 47 cases statewide. L.A. County officials have confirmed 28 cases.

Riverside County reported its first confirmed case of MIS-C just as students in the region start the school year online.

K-6 schools can seek waivers to reopen and must receive approval from the health department. Dozens of schools have applied and so far, five have been approved.

Dr. Cameron Kaiser, Riverside County’s public health officer, said of the county’s first case of MIS-C: “While this case is not known to be linked to any school, it’s a reminder we need to pay attention to COVID-19 in kids and its potential long- and short-term effects.”