• The novel coronavirus can cause a mysterious syndrome in some children that present itself a few weeks after a COVID-19 infection.
  • Known as multisystem inflammatory syndrome in children (MIS-C), the syndrome appears to be more dangerous than initially believed.
  • Researchers who studied known cases of MIS-C concluded that underlying conditions and obesity are the main risk factors, and many children will need ICU care. MIS-C can be fatal and can lead to long-lasting heart problems.

While it is true that children are less likely than adults to develop severe COVID-19 cases, they can still get infected and spread the illness to others. Even more worrisome is the fact that the danger doesn’t end once the novel coronavirus has cleared their systems. A mysterious condition that was first identified a few months ago by UK pediatricians can follow weeks later. It’s known as multisystem inflammatory syndrome in children (MIS-C), and it’s potentially fatal.

Brazilian doctors documented one such case in great detail this summer, showing how the virus infected the heart of an otherwise healthy 11-year-old girl as well as other organs. The young patient died less than 30 hours after being admitted to the hospital and after receiving some treatment for the condition.

It turns out that doctors may have hardly scratched the surface when it comes to studying and understanding MIS-C. The syndrome might be a lot more dangerous than we thought, and it can affect COVID-19 survivors who had a mild or asymptomatic case. What’s even more worrying is that the COVID-19 prognosis might not be a good indicator of how well a child will deal with MIS-C. And young patients who survive both COVID-19 and MIS-C might have residual health problems caused by the virus that might haunt them for years.

Researchers from the University of Texas Health Science Centre at San Antonio have reviewed the available medical research of MIS-C, ScienceAlert reports. The data was then published in EClinicalMedicine

The doctors found that “children did not need to exhibit the classic upper respiratory symptoms of COVID-19 to develop MIS-C, which is frightening,” according to Dr. Alvaro Moreira. “Children might have no symptoms, no one knew they had the disease, and a few weeks later, they may develop this exaggerated inflammation in the body.”

The team looked at 662 MIS-C cases reported worldwide between January 1st and July 25th and came up with a few disturbing findings. Some 71% of the children who were admitted to hospitals had to be cared for in intensive care units, and 60% of them presented with shock.

The average length of stay was of 8 days, and symptoms included fever (100% of patients), abdominal pain or diarrhea (73.7%), and vomiting (68.3%). EKGs were performed on 90% of patients, and 54% had abnormal results, which indicates heart issues were present.

More than 22% of children needed mechanical ventilation, and nearly 4.5% required a machine called extracorporeal membrane oxygenation (ECMO) that filters the blood to remove CO2 and replace it with oxygen.

The researchers also found that almost half of patients had underlying conditions, and that half of them were obese or overweight. Obesity seems to be a significant risk factor for COVID-19, as well.

Of those 662 cases, 11 were fatal, putting the overall fatality rate at 1.7%, which seems low if you don’t look at the COVID-19 fatality rate in children observed so far. That figure is 0.09%, according to a different study from June. That said, we’re not looking at true mortality rates here, because we have no idea how many children in the world were infected with coronavirus so far and how many died, and there may be plenty of MiS-C cases that were not treated in hospitals. Still, the researchers indicate that MIS-C might be more dangerous than COVID-19.

“This is a new childhood disease that is believed to be associated with SARS-CoV-2,” Dr. Moreira said. “It can be lethal because it affects multiple organ systems. Whether it be the heart and the lungs, the gastrointestinal system, or the neurologic system, it has so many different faces that initially it was challenging for clinicians to understand.”

The doctor also said that the amount of inflammation surpasses two similar conditions, Kawasaki disease, and toxic shock syndrome. But the similarities with these conditions allowed doctors to treat the patients using the same protocols. Immunoglobulin and glucocorticosteroid therapies seem to be effective in MIS-C.

Children who survived COVID-19 and MIS-C but who showed significant heart problems might remain with a heart condition that will need continued treatment. Some children may develop aneurysms or stretching of blood vessels. “These are children who are going to require significant observation and follow-up with multiple ultrasounds to see if this is going to resolve or if this is something they will have for the rest of their lives,” Moreira said. “And that’s catastrophic to a parent who had a previously healthy child and then he/she is in the very small percentage of individuals who developed MIS-C after COVID-19 infection.”

The researchers warn that MIS-C symptoms might show up three to four weeks after COVID-19 and “and many will progress rapidly into shock and cardiorespiratory failure. “Families should seek immediate medical care as children with this condition decompensate quickly, and most children will need management in an intensive care unit.”

Hundreds of thousands of children have tested positive for COVID-19 already, so MIS-C isn’t a widespread condition. But the new MIS-C study underscores the importance of proper testing, especially now that schools have reopened. If a child tests positive, parents and caretakers should keep an eye out for sudden symptoms in the weeks that follow, especially if underlying conditions and/or obesity are present.

Chris Smith started writing about gadgets as a hobby, and before he knew it he was sharing his views on tech stuff with readers around the world. Whenever he's not writing about gadgets he miserably fails to stay away from them, although he desperately tries. But that's not necessarily a bad thing.