Despite this, asthma severity was not associated with higher risk of COVID-19.
Additionally, the virus did not appear to be a strong trigger for pediatric asthma exacerbations, and asthma severity was not associated with a higher risk of COVID-19.
Investigators led by Erick Forno, MD, MPH, Division of Pulmonary Medicine, UPMC Children’s Hospital of Pittsburgh, added that a majority of pediatric studies of the 2 conditions have only been ecological, offering limited data.
Additionally, there have been conflicting reports on whether asthma increased COVID-19 risk or severity.
As such, Forno and colleagues set out to determine the association between asthma and COVID-19 at an individual level.
For the study, Forno and investigators extracted data from prospective clinical registries including the Western Pennsylvania COVID-19 Registry (WPACR) and the CPH Asthma Registry, the former of which was established in March 2020.
Data on children with pre-existing asthma who presented with COVID-19 between March and December 2020 were included in the study. For disease controls, children from the WPACR without pre-existing conditions who presented with the virus were included.
A nested case-control study compared 3 groups of children: those with COVID-19 and underlying asthma (A+C cases), children with COVID-19 without underlying disease (C+ controls), and children with asthma without COVID-19 (A+ controls).
The cohort included 142 A+C cases, 1110 C+ controls, and 140 A+ controls.
Investigators also abstracted electronic health data on baseline asthma severity, asthma controller medications, symptom control via the Asthma Control Test (ACT), lung function, and atopy biomarkers.
Asthma severity was defined by the National Asthma education and Prevention Program (NAEPP) guidelines. Asthma exacerbations were evaluated from January 1, 2018, to December 31, 2019, to avoid potential affects from the pandemic on poor asthma control.
Forno and colleagues reported that the A+C cases were more likely to present with dyspnea and wheezing than C+ controls.
Additionally, A+C cases were also more likely to receive pharmacologic treatment which including systemic steroids (all p<0.01), and to and to be hospitalized (4.9% vs 1.7%, p=0.01).
Overall, 26 children (2.1%) in the WPCAR were hospitalized during the study period. Compared to children with the virus who were not hospitalized, patients who were hospitalixed were more likely to have asthma (26.9% versus 11%).
In the adjusted analysis, investigators noted that A+C cases were nearly 4 times more likely to be hospitalized than C+ controls (adjusted OR=3.95 [95%CI=1.4-10.9]).
However, length of stay and respiratory support level did not differ between groups.
Among A+C cases, 8.5% presented with an asthma exacerbation, while another6.3% developed acute exacerbation symptoms shortly after testing positive for the COVID-19 virus.
Compared to A+ controls, A+C cases had less severe asthma and were less likely to be on controller medications. Additionally, A+C cases had better asthma symptom control (all p<0.01).
The study had preceded the emergence of the Delta variant, which prompted investigators to continue to analyze potential differences in future studies.
“With the advent of the Delta variant and current rise in COVID-19 cases, itwill be important to conduct multi-center, individual-level, case-control or cohort studies of COVID-19 and asthma to better understand this evolving disease and its impact on children with asthma,” the team wrote.
The study, “Asthma as a Risk Factor for Hospitalization in children with COVID-19: A Nested Case-Control Study,” was published online in Pediatric Allergy and Immunology.