No Association Identified Between COVID-19, Development of Asthma Among Children

SARS-CoV-2 polymerase chain reaction (PCR) test positivity is not linked to new diagnoses of asthma among children, according to recent findings, although known risk factors for asthma among this patient population are re-confirmed.¹

These findings were the conclusion of a new retrospective cohort study, the corresponding author of which was David A. Hill, MD, PhD, of the division of allergy and immunology at Children’s Hospital of Philadelphia. Hill and colleagues had aimed to find out whether infection with SARS-CoV-2 had any impact on pediatric incident risk of asthma.

The investigators noted that while there had been some research connecting chronic cough and asthma-like symptoms among young patients following SARS-CoV-2 hospitalization, there had not been research to date which evaluated the incidence of diagnosis following such infections in the pediatric population.²

“To address this knowledge gap, we used a large longitudinal pediatric cohort to ascertain whether children who tested positive for SARS-CoV-2 had altered rates of subsequent asthma diagnosis compared with those who tested negative for SARS-CoV-2 during the same interval,” Hill and colleagues wrote.

Background and Methods

The research team extracted the necessary data from the electronic health records of children in the age range of 1 - 16 years within the Children’s Hospital of Philadelphia (CHOP) Care Network from 2019 - 2022. Their work was centered on those who had been given PCR testing for SARS-CoV-2 infection in the time between March 2020 - February 2021.

Such a timeframe preceded the availability of routine rapid antigen testing as well as vaccination for patients in the pediatric population, with the team noting that all participants were considered unvaccinated at the time of the exposure window. In order to be included, subjects would have to have had at least a single ambulatory well-child visit within the CHOP Care Network (CCN) in the year prior to PCR testing and another CCN interaction within the span of an 18-month follow-up period following their initial positive or last negative PCR.

CCN follow-up meetings involved various settings such as telemedicine, urgent care, primary care, and inpatient admission. A 30 day gap between the 18-month follow-up timeframe and the corresponding PCR test was utilized to allow the investigators to make a clear distinction between the exposure and outcome times.

They worked to exclude instances in which diagnoses of asthma were found to coincide with SARS-CoV-2 testing. Diagnosis of asthma was mainly defined by the research team as the existence of an International Classification of Diseases (ICD) code for the lung condition at a CCN visit, in addition to a prescription for asthma-related treatment.

Such medications deemed to be asthma-related included inhaled corticosteroids, β agonists, leukotriene modulators, combined inhaled corticosteroids with long-acting β agonists, or biologic treatments. The investigators used a sensitivity analysis, implementing a secondary definition needing an ICD code for the condition during 2 or more follow-up meetings as well as asthma-connected prescriptions.

The research team also looked at demographic elements such as subjects’ ages, sex, races, and insurance status as part of their analysis.

Findings

Overall, the research team involved 27,423 participants in their analysis. Following an adjustment for confounding variables, such as SARS-CoV-2 positivity in PCR tests, the team showed that there had been no substantial effect of such an infection on patients’ likelihood of developing new asthma (hazard ratio [HR]: 0.96; P = .79).

Despite this encouraging finding, the investigators did connect certain factors with a higher hazard of new diagnoses of asthma. These factors included the presence of allergies to food (HR: 1.26; P = .025), being racially-defined as Black (HR: 1.49; P = .004), and having allergic rhinitis (HR: 2.30; P < .001).

The research team also found a substantial link between both preterm birth (HR: 1.48; P = .005) and higher body mass index (BMI) (HR: 1.13; P < .001) and an increased new asthma diagnosis hazard among children who were in the age range of 5 years or below.

“This study refines our knowledge regarding the long-term respiratory effects of SARS-CoV-2 infection in children and adds to our growing understanding of how SARS-CoV-2 may influence asthma development in pediatric patients,” they wrote. “Future work should consider SARS-CoV-2 infection severity and stratify between asymptomatic and symptomatic children and between those with mild, moderate, or severe symptoms.”

References

1. ^{James P. Senter, Laura K. Aisenberg, Jesse W. Dudley, Xianqun Luan, Jing Huang, Chén C. Kenyon, David A. Hill; COVID-19 and Asthma Onset in Children. Pediatrics 2024; e2023064615. 10.1542/peds.2023-064615.}
2. ^{Esmaeilzadeh H, Sanaei Dashti A, Mortazavi N, Fatemian H, Vali M. Persistent cough and asthma-like symptoms post COVID-19 hospitalization in children. BMC Infect Dis. 2022;22(1):244.}