More reports of the unexpected inflammatory condition seen in a small number of children with the coronavirus infection are shedding light on common characteristics of the children. A new study from Paris found that black children appear disproportionately more likely to develop the symptoms than other children. These findings echo the pattern seen in adults where black patients tend to have more severe disease and a higher death rate from COVID-19 than white patients, largely due to health disparities from a history of racism.
News reports began appearing in early May about the condition, which has symptoms similar to what is seen with Kawasaki syndrome, whose symptoms include fever rash, swelling in the hands and feet, swollen lymph nodes in the neck, inflammation of the mouth, lips and throat. Without treatment—immunoglobulin through IV and aspirin—children can develop serious heart problems or aneurysms. The CDC has begun calling the new condition multi-system inflammatory syndrome in children associated with COVID-19.
The researchers reported the medical, laboratory and other characteristics of 21 children under 18 in Paris, France who had the Kawasaki-like inflammatory symptoms that doctors have recently identified in a small subset of children with COVID-19.
The average age of the children was 8 years old, but more than half of them (57%) had African ancestry. Less than a quarter of the children were overweight, so the researchers concluded that children’s weight does not appear to affect their outcomes from the coronavirus infection.
Most of the children admitted to the hospital (81%) needed intensive care, and all of them had gastrointestinal problems soon after first getting sick. More than half of them (57%) had Kawasaki disease shock syndrome, a condition where children’s systolic blood pressure was 20% lower than average. A majority of the children (76%) also had inflammation of the heart.
All but two of the children had positive COVID-19 tests. They all received the standard treatment for Kawasaki disease—immunoglobulin through an IV—and just under half of them (48%) received corticosteroids. All of the children were recovered and ultimately discharged home.
The researchers noted that COVID-19 does appear to cause the Kawasaki symptoms given the proportion of positive test results and the uptick in these cases since the pandemic hit France.
Yet only one of the children had active symptoms of COVID-19—and most of them had positive antibody tests. This finding suggests that the children are developed Kawasaki disease due to an immune reaction that resulted from fighting the virus. Many of the COVID-19 deaths in adults occur due to a cytokine storm, a severe overreaction of one part of the immune system as it tries to stave off the virus. It’s possible that a similar mechanism in children who have the coronavirus infection is leading to these Kawasaki-like symptoms, the authors speculated.
“An association between Kawasaki disease and viral respiratory infections has been suspected, especially rhinovirus and enterovirus, and various viral agents, including human coronaviruses,” the authors wrote. But the research literature does not include any comparisons between children with Kawasaki syndrome who do versus don’t have a respiratory viral infection.
It’s also unclear why a higher proportion of black children developed this post-COVID-19 condition than non-black children.The hospital where the patients were admitted is the primary hospital for all children with COVID-19 in the Paris area, so it’s unlikely to be affected by different neighborhood demographics. The authors speculate that it could be “an effect of either social and living conditions or genetic susceptibility.”
Yet Kawasaki condition isn’t commonly reported in sub-Saharan Africa, which casts the genetic component in doubt. It might be more common than realized but not diagnosed, or it might be more connected to children’s living conditions. In the US, black children already suffer greater rates of obesity, asthma, and diabetes due to systemic social factors resulting from the history of racism in the US.
Previous studies specifically of Kawasaki syndrome in the US—unrelated to COVID-19—have found it occurs 2.5 times more often in children of Asian descent than in white children, and 1.5 times more often in black children. Yet the disease is reported less often in Asian countries than in Western countries.
If it does turn out to have a genetic component, the authors note that supply shortages of immunoglobulin could occur in African countries dealing with COVID-19 if they start seeing more of these cases in children.