A large nationwide study found important differences in the two main causes of serious illness in children from the coronavirus. These results can help doctors and parents better identify the conditions and understand more about the children at risk.
The study, published Wednesday in JAMA magazine, analyzed 1,116 cases of young people being treated in 66 hospitals in 31 states. Just over half of the patients had acute Covid-19, the predominantly lung-related disease that affects most adults with the virus, while 539 patients had the inflammatory syndrome, which in some children follows a typical mild one weeks Disease broke out, initial infection.
The researchers found some similarities, but also significant differences, in the symptoms and characteristics of the patients, who ranged from infants to 20-year-olds who were hospitalized between March 15 and October 31 last year.
Young people with the syndrome known as Pediatric Multisystem Inflammatory Syndrome, or MIS-C, were more likely to be between 6 and 12 years old, while more than 80 percent of patients with acute Covid-19 were either younger than 6 years or older were as 12.
More than two-thirds of patients with both conditions were Black or Hispanic, which experts say most likely reflects socio-economic and other factors that some communities have disproportionately exposed to the virus.
“It is still shocking that the vast majority of patients are not white, and that goes for MIS-C and for acute Covid,” said Dr. Jean A. Ballweg, Medical Director, Pediatric Heart Transplant and Advanced Heart Failure at Children’s Hospital & Medical Center in Omaha, who was not involved in the study. “There are clearly racial differences.”
For unclear reasons, while Hispanic adolescents appeared to be equally at risk for both conditions, black children appeared to be at greater risk for developing the inflammatory syndrome than the acute disease, said Dr. Adrienne Randolph, the study’s lead author and a specialist in pediatric intensive care at Boston Children’s Hospital.
One possible clue that the authors mention is that in Kawasaki disease, a rare childhood inflammatory syndrome that shares similarities with some aspects of MIS-C, black children are more likely to have cardiac abnormalities and are less responsive to one of the standard treatments: intravenous Immunoglobulin.
The researchers found that young people with the inflammatory syndrome were significantly more likely to have no underlying illnesses than those with acute Covid. Nevertheless, more than a third of patients with acute Covid had no previous illness. “It’s not that previously healthy children are completely unscathed here,” said Dr. Randolph.
In the study, obesity was assessed separately from other underlying health conditions and only in patients 2 years and older. It found that a slightly higher percentage of young people with acute Covid were obese.
Updated
Apr. 26, 2021 at 1:54 am ET
Dr. Srinivas Murthy, an associate professor of pediatrics at the University of British Columbia who was not involved in the study, said he was not convinced the results show that healthy children are at higher risk for MIS-C. It could “mostly be a numbers game where the proportion of infected children and the proportion of healthy children is out there, instead of saying that healthy children have something immune that puts them at disproportionately higher risk,” he said.
Overall, the study’s documentation of the differences between the two conditions was useful, especially because it reflected “a reasonably representative group of hospitals in the US.”
Young people with the inflammatory syndrome were more likely to have had to be treated in intensive care units. Her symptoms more commonly included gastrointestinal problems and inflammation, as well as skin and mucous membranes. They were also much more likely to have heart problems, although many of the acute Covid patients didn’t get detailed heart exams, the study said.
About the same large proportion of patients with any disease – more than half – required airway support, with slightly less than a third of patients requiring mechanical ventilation. About the same small number of patients in each group died: 10 with MIS-C and eight with acute Covid-19.
The data does not reflect a recent surge in inflammatory syndrome cases that followed a surge in total Covid-19 infections across the country during the winter holiday season. Some hospitals have reported that there were more seriously ill MIS-C patients in the current wave compared to previous waves.
“I’ll be intrigued to see a comparison with this group from November 1st because I think we all felt that the kids with MIS-C have been even sicker lately,” said Dr. Ball path.
An optimistic sign from the study was that most severe heart problems in young people with inflammatory syndrome improved to normal within 30 days. Dr. However, Randolph said any remaining effects are still unknown, which is why one of her co-authors, Dr. Jane Newburger, assistant director of academic affairs in the cardiology department at Boston Children’s Hospital, conducted a statewide study to track children with inflammatory syndrome for up to five years.
“We can’t say 100 percent for sure that everything will be normal in the long run,” said Dr. Randolph.
