Children and adolescents diagnosed as having asthma are at similar risk for COVID-19 infection as those without asthma, according to a study today in Pediatrics that controlled for factors tied to SARS-CoV-2 testing.
The prepublication peer-reviewed study, conducted by Duke University researchers, involved retrospective review of the electronic health records of 46,900 children 5 to 17 years old in North Carolina, of whom 6,324 (13.5%) had asthma, to identify COVID-19 diagnoses from Mar 1, 2020, to Sep 30, 2021.
The study period spanned the emergence and dominance of the Delta SARS-CoV-2 variant but was before Omicron.
A total of 10,566 (22.5%) children were tested at least once for COVID-19. Pediatric asthma patients were more likely than those without asthma to undergo COVID-19 testing (33.0% vs 20.9%). Children of "other" racial minority groups and those with self-pay insurance were less likely to be tested for COVID-19, while those with public insurance and higher neighborhood deprivation index scores were more likely to undergo testing.
A total of 1,864 children (4.0%) tested positive for COVID-19, including 350 (5.5%) with asthma and 1,514 (3.7%) without asthma.
Among the 1,864 patients who tested positive for COVID-19, 34 (1.8%) were hospitalized within 30 days, 3 of whom had asthma. Of these children, 8 (0.5%) were hospitalized for treatment of COVID-19, including 7 of 1,514 children without asthma (0.5%) and 1 of 350 with asthma (0.3%). One child without asthma was hospitalized for treatment of multisystem inflammatory syndrome in children (MIS-C).
Equal proportion of infection with, without asthma
Relative to children without asthma, those with asthma were more likely to be boys (58% vs 50%), to be Black (56% to 37%), have public insurance (59% vs 49%), have had a well-child visit in the last 2 years (73% vs 52%), and to have had more healthcare visits in the preceding year (median, 3 vs 1).
In a propensity score-matched cohort of 12,648 children, 706 (5.6%) tested positive for COVID-19, 350 (2.8%) of whom had asthma, and 356 (2.8%) of whom did not (risk ratio, 0.98; 95% confidence interval, 0.85 to 1.13). These results weren't modified by inhaled corticosteroid prescription, history of severe asthma exacerbation, or coexisting allergic disease.
The study authors noted that asthma is the most common chronic condition and a leading cause of hospitalization among children and adolescents. While the study didn't show an increased risk for COVID-19 infection among asthma patients, the researchers said that asthma could mitigate infection risk through reduced levels of cell surface proteins that mediate SARS-CoV-2 cell entry.
In addition, inhaled corticosteroids could dampen host inflammatory responses and decrease viral replication, and infection-prevention behaviors that may be common among children with asthma could reduce the risk of infection.
"Despite the continued general precaution regarding asthma and COVID-19, we found no evidence that asthma predisposes children to SARS-CoV-2 infection or severe illness from COVID-19," the researchers wrote. "Importantly, we identified marked disparities in SARS-CoV-2 testing based on sociodemographic factors, highlighting the need for improved access to SARS-CoV-2 testing and care among certain vulnerable pediatric populations."
The authors called for further research to evaluate the relationship between chronic medical conditions such as asthma and SARS-CoV-2 infection and to monitor the effect of variants and vaccination strategies on COVID-19 infection in children.