One child, 8 years old, arrived at a Long Island hospital near death last week. His brother, a Boy Scout, had begun performing chest compressions before the ambulance crew arrived.

In the past two days alone, the hospital, Cohen Children’s Medical Center, has admitted five critically ill patients — ages 4 to 12 — with an unusual sickness that appears to be somehow linked to COVID-19, the disease caused by coronavirus. In total, about 25 similarly ill children have been admitted there in recent weeks with symptoms ranging from reddened tongues to enlarged coronary arteries.

Since the coronavirus pandemic began, most infected children have not developed serious respiratory failure of the kind that has afflicted adults. But in recent weeks, a mysterious new syndrome has cropped up among children in Long Island, New York City and other hot spots around the country, in an indication that the risk to children may be greater than anticipated.

The number of children in the United States showing signs of this new syndrome — which first was detected in Europe last month — is still small, and none is known to have died.

“This is really only a disease that has been clear for two weeks now, so there is so much we’re trying to learn about this,” the chief of pediatric critical care at Cohen Children’s, Dr. James Schneider, said in an interview Tuesday.

No solid data yet exists about how many children in the United States have fallen ill with what doctors are calling “pediatric multisystem inflammatory syndrome.”

Advertising

In some patients the syndrome seems to match a rare childhood illness called Kawasaki disease, which can lead to inflammation of the blood vessels, especially the coronary arteries.

The symptoms of Kawasaki disease often start with a fever and a rash, but when undiagnosed and untreated, the illness can lead to serious heart conditions, such as coronary aneurysms. The disease, which generally afflicts patients 6 months to about 6 years old, is considered rare in the United States.

While some patients in recent weeks have presented as if they had classic Kawasaki disease, others have been far more seriously ill, with falling blood pressure, heart inflammation and symptoms consistent with toxic shock, said Dr. Nadine Choueiter of the Children’s Hospital at Montefiore in the Bronx.

Dr. Steven Kernie, chief of pediatric critical care medicine at Columbia University and NewYork-Presbyterian Morgan Stanley Children’s Hospital, which has treated between 10 and 20 children with the condition, said it was important to distinguish between this coronavirus-related condition and Kawasaki disease.

While some of the symptoms are similar, Kernie said — including fever, abdominal pain and sometimes a raised rash — there appear to be differences in how the coronavirus-related condition affects the heart.

While shock is a rare complication of Kawasaki disease, in the recent wave of coronavirus-related cases, he said, many of the children are in shock with very low blood pressure and an inability of the blood to effectively circulate oxygen and nutrients to the body’s organs.

Advertising

On Monday night, the New York City Health Department issued a bulletin, asking doctors to report any cases of the syndrome. The bulletin said the health authorities in the city knew of 15 such cases, involving patients age 2 to 15, who had been in intensive care units since April 17.

But based on interviews with doctors, the number of cases in the city appears to be higher than 15.

“I would say so far we have seen 13 patients,” Choueiter said of the number of children treated for the syndrome at just her hospital.

Still, doctors were reluctant to speculate how widespread it might be across the city. “That is the question we are constantly thinking about, and I don’t think we know the answer,” Choueiter said.

In Richmond Hill, Queens, Jayden Hardowar, 8, initially had only a mild fever, starting on April 23, his father, Roup Hardowar, said.

But several days later, Jayden started to grow very weak and listless. On April 29, he was lying in bed watching a Pokemon TV episode. “Mommy,” he cried out, before he stopped breathing. His face started turning purple. His 15-year-old brother, a Boy Scout, began performing chest compressions, stopping only when the ambulance arrived, his father said.

Advertising

At Cohen’s Hospital, in New Hyde Park, Jayden was put on a mechanical ventilator for three days before he began to improve. Although Jayden tested negative for the coronavirus, he tested positive for antibodies, suggesting he might have been infected with the virus in recent weeks or months, his father said.

In recent days, Jayden has begun to open his eyes and smile or cry at his parents during video chats arranged by a nurse. “Last night he said, ‘I love you, Mommy,’ his father recounted Tuesday.

Jayden is one of 11 children in the intensive care unit at Cohen Children’s deemed to have the syndrome, doctors there said.

Similar cases are appearing elsewhere in the country, too.

Juliet Daly, a healthy 12-year-old from Covington, Louisiana, woke up on April 3 with such sharp pains in her stomach that she had trouble moving. “I spent one hour in bed trying, attempting to get up, and I spent half an hour going down the stairs,” Juliet said in an interview Tuesday.

Over the weekend, she had a fever, and, she said, “I couldn’t eat and I couldn’t drink because I vomited everything up.” By Monday, “my arms were cold and my lips were blue,” she said.

She was so lethargic that “she kind of fell asleep in the bath,” said her father, Sean Daly.

Sponsored

The family took Juliet to a nearby hospital, where they were told that she was experiencing an acute form of heart inflammation called fulminant myocarditis. Her heart rate was very low, and her heart was failing to pump blood.

The hospital decided to put Juliet on a ventilator and airlifted her to a medical center in New Orleans, about 40 miles south. During the intubation procedure, her heart stopped, and “she went into arrest for a little under two minutes,” Daly said. Later, on the helicopter, her heart stopped again and she needed to be revived by CPR, he said.

After nine days in the hospital, she returned home to her parents and two brothers. “I was able to walk around, but I was still wobbly,” she said. Now, Juliet, who likes to bike and do artwork, is feeling healthy.

Doctors in New York have noted that cases of the new syndrome began to appear a month or so after a surge of COVID-19 in the region. That timing suggests “it’s a post-infectious immune response to this,” said Dr. Leonard Krilov, chairman of pediatrics at NYU Winthrop Hospital in Mineola, New York.

Early research suggests that children are significantly less likely to become seriously ill with COVID-19 than adults. In New York City there have been 13,724 deaths of laboratory-confirmed COVID patients. Six have been 17 years old or younger, and all had underlying health conditions, according to city data.

Doctors say that even though there is growing evidence that some healthy children are falling gravely ill with this new syndrome, they are still at far less risk from COVID-19 than adults.

“It’s just a different disease in adults,” said Dr. Jennifer Lighter, a pediatric infectious disease specialist at NYU Langone, who treated one pediatric patient with the syndrome last week. Of the new syndrome, she said, “It is very, very rare, and the children have been doing OK for the most part.”