Data Remain Unclear Between Asthma Incidence, Prevalence, and COVID-19

Ashley Gallagher;

Data Remain Unclear Between Asthma Incidence, Prevalence, and COVID-19

April 8, 2025

By Ashley Gallagher

Publication

Article

Drug Topics JournalDrug Topics March/April 2025

Volume 169

Issue 02

Conflicting study findings show various associations between asthma and COVID-19; further data are needed.

The incidence and prevalence of asthma increased globally, especially for children under 5 years of age and high sociodemographic index regions, during the COVID-19 pandemic, according to study results published in Public Health.¹

Conflicting study findings show various associations between asthma and COVID-19; further data are needed. | Image Credit: Crystal light - stock.adobe.com

“This is a complicated issue, in my opinion. I am not jumping on the bandwagon yet, as I think we need to see what happens over the next 3 to 5 years,” Dennis Williams, PharmD, BCPS, AE-C, associate professor at Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill, said in an interview. “What we do know is this: (1) It is reasonable to think that COVID-19 can impact the prevalence of asthma; (2) the SARS-CoV-2 virus has a significant immunologic effect, especially in the lung; and (3) people who are at risk for bronchial hyperreactivity—a feature of asthma—would be expected to be susceptible. ”

Asthma, allergies, and other respiratory illnesses, such as COVID-19, influenza, or respiratory syncytial virus (RSV), can have similar symptoms, according to the Asthma and Allergy Foundation of America. Symptoms of asthma and COVID-19 can include dry cough, shortness of breath, or trouble breathing. COVID-19 can be accompanied by flu-like symptoms, such as runny nose, fever, and sore throat. Many studies show that asthma does not increase the risk of severe illness or contracting COVID-19, but COVID-19 can cause asthma episodes similarly to influenza and RSV.²

Study investigators used data from the Global Burden of Disease Study 2021, including viral registrations, verbal autopsies, surveys, censuses, surveillance systems, and cancer registries. The authors found that the global age-standardized incidence rate (ASIR), AS prevalence rate (ASPR), and AS death rate (ASDR) of asthma was approximately 516.70 per 100,000, 3340.12 per 100,000, and 5.2 per 100,000 individuals, respectively, in 2021. Regions of high sociodemographic index had the highest ASIR and ASPR at 879.28 per 100,000 and 6755.31 per 100,000, respectively, and low-middle sociodemographic index and low sociodemographic index regions had the highest ASDRs at 15.71 per 100,000 and 16.5 per 100,000, respectively.¹

Compared with before the pandemic, the global ASIRs and ASPRs of asthma increased to 5.26 per 100,000 and 23.10 per 100,000, respectively; however, the global ASDR decreased slightly, at –0.30 per 100,000 during the pandemic. For the United States, the ASIR increased to 17.63 per 100,000 during the pandemic.¹

In another study, investigators found that COVID-19 infection may, in rare cases, cause new-onset asthma, possibly linked to eosinophilic inflammation, according to results published in the Journal of Allergy and Clinical Immunology: In Practice. Between April 1, 2022, and October 30, 2022, investigators included 394 patients who recovered from the acute phase of COVID-19 and visited a pulmonology or allergy outpatient clinic.³

“I haven’t seen an increase in asthma diagnoses. In fact, some interesting things happened during the pandemic,” Williams said in the interview. “It is interesting that…other publications…report that the risk for an asthma exacerbation decreased during the pandemic. The theory is that people were wearing masks and were less socially active, so they were exposed less to other viruses [that] could cause an increase in symptoms.”

Approximately 36 patients were suspected of having asthma, but 16 were excluded due to previous asthma diagnosis and 3 for symptoms of asthma before COVID-19 infection. Seventeen people were identified with a possible new asthma diagnosis, and 6 were confirmed to have asthma. The investigators concluded that COVID-19 infection rarely causes asthma, but it could be linked to inflammation due to the elevated absolute eosinophil count and fractional exhaled nitric oxide.

“Now we have circulating viruses that many patients are at risk for, including [patients with] asthma. So that makes the influenza vaccine, RSV vaccine, and COVID-19 vaccine important,” Williams said. “Now, with the H5N1—bird flu—virus emerging, this is also going to be a problem in asthma. So pharmacists can provide information about how to protect [oneself] against respiratory viruses, [receive] the appropriate vaccines and [stay] up to date, and [ensure] good adherence to asthma therapies.

To read these stories and more, download the PDF of the Drug Topics March/April issue here.

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