More evidence has linked the Kawasaki-like multisystem inflammatory syndrome in children to COVID-19 and suggests that black children have a greater risk of the condition, according to a study published in the BMJ.
A small observational study in Paris found more than half of the 21 children who were admitted for the condition at the city’s pediatric hospital for COVID-19 patients were of African ancestry.
“The observation of a higher proportion of patients of African ancestry is consistent with recent findings, suggesting an effect of either social and living conditions or genetic susceptibility,” wrote Julie Toubiana, MD, PhD, of the University of Paris and the Pasteur Institute, and colleagues.
The findings did not surprise Edward M. Behrens, MD, chief of the division of rheumatology at Children’s Hospital of Philadelphia, whose institution has seen similar disparities that he attributes to social disadvantages.
“Infection rate will be higher in vulnerable populations that are less able to socially distance, have disproportionate numbers of essential workers, and have less access to health care and other resources,” Dr. Behrens said in an interview. “While there may be a role for genetics, environment – including social disparities – is almost certainly playing a role.”
Although the study’s small size is a limitation, he said, “the features described seem to mirror the experience of our center and what has been discussed more broadly amongst U.S. physicians.”
Byron Whyte, MD, a pediatrician in private practice in southeast Washington, found the differences in race interesting, but said the study was too small to draw any conclusions or generalize to the United States. But social disparities related to race are likely similar in France as they are in the United States, he said.
The prospective observational study assessed the clinical and demographic characteristics of all patients under age 18 who met the criteria for Kawasaki disease and were admitted between April 27 and May 20 to the Necker Hospital for Sick Children in Paris.
The 21 children had an average age of 8 years (ranging from 3 to 16), and 57% had at least one parent from sub-Saharan Africa or a Caribbean island; 14% had parents from Asia (two from China and one from Sri Lanka). The authors noted in their discussion that past U.S. and U.K. studies of Kawasaki disease have found a 2.5 times greater risk in Asian-American children and 1.5 times greater risk in African-American children compared with children with European ancestry.
Most of the patients (81%) needed intensive care, with 57% presenting with Kawasaki disease shock syndrome and 67% with myocarditis. Dr. Toubiana and associates also noted that “gastrointestinal symptoms were also unusually common, affecting all of our 21 patients.”
Only nine of the children reported having symptoms of a viral-like illness when they were admitted, primarily headache, cough, coryza, and fever, plus anosmia in one child. Among those children, the Kawasaki symptoms began a median 45 days after onset of the viral symptoms (range 18-79 days).
Only two children showed no positive test result for current COVID-19 infection or antibodies. Eight (38%) of the children had positive PCR tests for SARS-CoV2, and 19 (90%) had positive tests for IgG antibodies. The two patients with both negative tests did not require intensive care and did not have myocarditis.
About half the patients (52%) met all the criteria of Kawasaki disease, and the other 10 had “incomplete Kawasaki disease.” The most common Kawasaki symptoms were the polymorphous skin rash, occurring in 76% of the patients, changes to the lips and oral cavity (76%), and bilateral bulbar conjunctival injection (81%). Three patients (14%) had pleural effusion, and 10 of them (48%) had pericardial effusion, Dr. Toubiana and associates reported.
But Dr. Behrens said he disagrees with the assertion that the illness described in the paper and what he is seeing at Children’s Hospital of Philadelphia is related to Kawasaki disease.
“Most experts here in the U.S. seem to agree this is not Kawasaki disease, but a distinct clinical syndrome called multisystem inflammatory syndrome in children, or MIS-C, that seems to have some overlap with the most nonspecific features of Kawasaki disease,” said Dr. Behrens, who is the Joseph Lee Hollander Chair in Pediatric Rheumatology at Children’s Hospital of Philadelphia. He has coauthored a study currently under review and available as a preprint soon that examines the biologic mechanisms underlying MIS-C.
Neither Dr. Behrens nor Dr. Whyte believed the findings had clinical implications that might change practice, but Dr. Whyte said he will be paying closer attention to the black children he treats – 99% of his practice – who are recovering from COVID-19.
“And, because we know that the concerns of African Americans are often overlooked in health care,” Dr. Whyte said, physicians should “pay a little more attention to symptom reporting on those kids, since there is a possibility that those kids would need hospitalization.”
All the patients in the study were treated with intravenous immunoglobulin, and corticosteroids were administered to 10 of them (48%). Their median hospital stay was 8 days (5 days in intensive care), and all were discharged without any deaths.
“Only one patient had symptoms suggestive of acute covid-19 and most had positive serum test results for IgG antibodies, suggesting that the development of Kawasaki disease in these patients is more likely to be the result of a postviral immunological reaction,” Dr. Toubiana and associates said.
The research received no external funding, and neither the authors nor other quoted physicians had any relevant financial disclosures.
SOURCE: Toubiana J et al. BMJ. 2020 Jun 3, doi: 10.1136 bmj.m2094.