What Is Kawasaki Disease? Signs of Condition Seen in Children With Unexplained Illness Linked to COVID-19

Over a dozen children in New York City have developed an unexplained syndrome thought to be linked to COVID-19 according to health officials, with some patients showing features of a rare illness known as Kawasaki disease.

What is known as a "multi-system inflammatory syndrome" was reported in 15 two to 15-year-olds between April 17 and May 1, Dr. Demetre C. Daskalakis, deputy commissioner in the Division of Disease Control at New York City Health Department, wrote in a health alert for pediatricians. None of the children were reported to have died.

A multi-system inflammatory syndrome is where the immune system gives off proteins called cytokines at levels that mess with bodily functions. This can cause blood vessels to leak, leading to low blood pressure. Fluid can then accumulate in the lungs and other organs, with some patients requiring intensive care treatment to support their organs.

The cases were identified after the NYC Health Department contacted pediatric intensive care units between April 29 and May 3. The patients needed heart and/or respiratory support.

The alert comes after the syndrome was reported in children in the U.K. Daskalakis said cases were identified "elsewhere in the U.S.," but didn't specify a location.

In New York City, four patients tested positive for the coronavirus that causes COVID-19, 10 were negative, and one was indeterminate then tested negative. Healthcare workers found antibodies against the coronavirus in six patients who tested negative for the bug.

Daskalakis said that the patients' conditions varied depending on which organ system was affected, but included features of Kawasaki disease and shock. He said: "The full spectrum of disease is not yet known."

State health commissioner Dr. Howard A. Zucker told the New York Times officials were investigating the syndrome.

Last week, Dr. Maria Van Kerkhove, an infectious disease epidemiologist who works for the World Health Organization, told reporters at a press briefing: "There are some recent rare descriptions of children in some European countries that have had this inflammatory syndrome, which is similar to the Kawasaki syndrome, but it seems to be very rare."

What is Kawasaki disease?

Kawasaki disease is characterized by inflammation in the coronary arteries and other blood vessels. It mostly affects children around the age of two, but has also been found in some teens, according to the American Heart Association. Although all children are at risk, it is most common in those of Japanese and Asian descent. Most children with Kawasaki disease fully recover, but urgent medical treatment is needed to prevent significant heart problems.

Also known as Kawasaki syndrome or mucocutaneous lymph node syndrome, symptoms include a fever, rash, swollen hands and feet, red and irritated eyes, swollen lymph glands in the neck, and irritated and inflamed mouth, lips, and throat, the U.S. Centers for Disease Control states.

In the multi-system inflammatory syndrome patients in New York City, all had experienced a fever, and over half had a rash, stomach pain, vomiting, or diarrhea. Less than half had problems with their respiratory system.

Daskalakis said if pediatricians suspect a patient has the mysterious inflammatory syndrome, they should immediately be referred to a specialist in pediatric infectious disease, rheumatology, and/or critical care.

"Early diagnosis and treatment of patients meeting full or partial criteria for Kawasaki disease is critical to preventing end-organ damage and other long-term complications," he said.