Doctors in Europe, New York report rare cases of pediatric inflammatory condition, possibly caused by coronavirus

Fifteen children in New York City have been hospitalized for what officials called a “multi-system inflammatory syndrome” that the local health department is investigating as a possible consequence of a Covid-19 infection. Doctors in Europe have recently reported similar cases — the latest potential twist in the coronavirus pandemic.

The children in New York, ages 2 to 15, had high fevers and elevated levels of inflammatory markers, signs that are common in shock and an acute pediatric heart condition called Kawasaki disease, the city’s health department said Monday. The patients, who were hospitalized from April 17 to May 1, also showed symptoms including rash, abdominal pain, vomiting, and diarrhea. Five of the children had to be placed on ventilators; none have died.

Only four of the patients tested positive for an active case of Covid-19, but six of the negative cases showed evidence of a previous infection based on blood tests.

The bulletin from New York came after pediatricians in the United Kingdom and other European countries warned of a small increase in the number of critically ill children there also showing signs of shock or Kawasaki disease. Some had tested positive for the coronavirus.

“What we’ve asked for is for the global network of clinicians to be on alert for this and to ensure that they capture information on children systematically so that we can better understand what is occurring in children and so that we can better improve our understanding and guide treatment,” Maria Van Kerkhove, a World Health Organization coronavirus expert, said at a briefing last week. She said that the cases reported in Europe appeared to be rare.

Overall, children are thought to have much milder Covid-19 infections than adults, with some portion not even showing symptoms. Researchers are still investigating whether or not that means they spread the virus less efficiently than infected adults.

The bulletins issued by New York City’s health department and a group of British pediatricians warned clinicians to be on the lookout for signs of Kawasaki disease, which can be difficult to diagnose. Other public health agencies have also started to inform providers about the possible connection between Covid-19 and the condition and are asking them to report suspected cases. It’s likely that as doctors review hospitalizations of sick children, more examples will come to light.

“Pediatricians, and particularly those at medical centers where these cases would most likely be seen, have been alerted to this through multiple channels,” said Larry Madoff, the medical director of the Massachusetts Department of Public Health’s Bureau of Infectious Disease and Laboratory Sciences. He said the department has not been informed of any cases in the state so far.

Kawasaki disease causes inflammation in arteries, particularly those that supply the heart with blood. If it’s not treated quickly, it can lead to blocked blood flow and heart damage. It’s most common in children under 5, but can affect teenagers as well.

There is no known cause for the disease, but it’s thought that it occurs when an infection causes the body’s own immune system to overreact. In people with serious Covid-19 infections, much of the widespread organ damage is similarly caused not directly by the virus, but by the immune reaction heading into overdrive.

“We do not yet know if the coronavirus produces a similar immune response in children,” Michael Portman, a pediatric cardiologist and director of the Kawasaki Disease Clinic at Seattle Children’s Hospital, said on the hospital’s blog last week. “Adults with the coronavirus often show a massive immune response, which is in some ways similar to that occurring in children with Kawasaki disease.”

Jane Burns, a pediatrician and director of the University of California, San Diego’s Kawasaki Disease Research Center, wrote last week that Covid-19 “may be a trigger for some children to develop KD,” in line with how there were different triggers for different children based on genetics.

But, she added, “there is no information to suggest that children who have had KD are at increased risk for complications of Covid-19 infection compared to the general population.”