Fifteen children have been hospitalized in New York with a rare inflammatory disease possibly linked to coronavirus, officials said Tuesday, in the latest reports of the worrying syndrome.

Kawasaki disease is a mysterious illness that primarily affects children up to the age of five and causes the walls of arteries to become inflamed, resulting in fever, skin peeling and joint pain.

Britain's National Health Service first sounded the alarm last month, warning about a small rise in children infected with the coronavirus that have "overlapping features of toxic shock syndrome and atypical Kawasaki disease."

France has also reported several cases.

Though frightening, most recover without serious issues.

New York's government health department said it had identified 15 cases of children aged between two and 15 who had symptoms of Kawasaki disease.

"That is enough for sure (to say) it's causing us concern," Mayor Bill de Blasio told reporters.

Four of the patients tested positive for COVID-19, the health department said in a statement.

Six of the ten who tested negative were found to have antibodies, suggesting they had previously been infected with COVID-19.

More than half of the patients required blood pressure support and five needed mechanical ventilation, but no fatalities were reported among the cases, the department said.

Respiratory symptoms were reported in less than half the patients, it said. All experienced a fever and more than half reported rash, abdominal pain, vomiting, or diarrhea. 

New York City Health Commissioner Oxiris Barbot said a few cases had also been identified in Boston and Philadelphia.

"We're not sure what to make of this yet. We're still learning everyday about how COVID-19 behaves," she said.

Treatment for Kawasaki disease involves intravenous immunoglobulin and aspirin, Barbot added.