County Public Health Director Dr. Barbara Ferrer said that 21 suspected cases have been identified across the region since March 1. The four children were diagnosed with coronavirus through antibody testing, but investigations on the remaining suspected cases are ongoing.
The connection between coronavirus and the new condition, which is similar to Kawasaki Disease, a rare syndrome that turns a child's immune system against its blood vessels, has led to a new diagnosis that doctors are trying to quickly learn more about.
The condition has been called PIMS, for Pediatric Inflammatory Multi-System Syndrome. Kawasaki symptoms include: persistent high fever, rash, red cracked lips, red tongue, swollen eyes, hands and feet, and enlarged lymph nodes in the neck.
All four of the county's cases appear to have occurred at Children's Hospital Los Angeles, which confirmed last week a fourth patient. The hospital reported three cases of the condition earlier this month, and all three of those patients -- between the ages of 8 months and 2 years old -- have since been discharged.
The fourth patient was being treated as of last week, listed in critical condition.
CHLA officials have said the four patients all tested positive for COVID-19 antibodies, indicating that were infected with the coronavirus at some point, prompting speculation that PIMS could be a delayed response by the body to the illness.
In New York, dozens of potential cases have been reported and three associated deaths among two children and a teenager.
Local doctor explains what you should know about rare condition in kids linked to COVID-19
City News Service contributed to this report.