Allergic disorders and susceptibility to and severity of COVID-19: A nationwide cohort study

Abstract

Background: There is inconclusive and controversial evidence of the association between allergic diseases and the risk of adverse clinical outcomes of coronavirus disease 2019 (COVID-19).

Objective: We sought to determine the association of allergic disorders with the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and with clinical outcomes of COVID-19 (admission to intensive care unit, administration of invasive ventilation, and death).

Methods: A propensity-score-matched nationwide cohort study was performed in South Korea. Data obtained from the Health Insurance Review & Assessment Service of Korea from all adult patients (age, >20 years) who were tested for SARS-CoV-2 in South Korea between January 1, 2020, and May 15, 2020, were analyzed. The association of SARS-CoV-2 test positivity and allergic diseases in the entire cohort (n = 219,959) and the difference in clinical outcomes of COVID-19 were evaluated in patients with allergic diseases and SARS-CoV-2 positivity (n = 7,340).

Results: In the entire cohort, patients who underwent SARS-CoV-2 testing were evaluated to ascertain whether asthma and allergic rhinitis were associated with an increased likelihood of SARS-CoV-2 test positivity. After propensity score matching, we found that asthma and allergic rhinitis were associated with worse clinical outcomes of COVID-19 in patients with SARS-CoV-2 test positivity. Patients with nonallergic asthma had a greater risk of SARS-CoV-2 test positivity and worse clinical outcomes of COVID-19 than patients with allergic asthma.

Conclusions: In a Korean nationwide cohort, allergic rhinitis and asthma, especially nonallergic asthma, confers a greater risk of susceptibility to SARS-CoV-2 infection and severe clinical outcomes of COVID-19.

Keywords: COVID-19; allergic rhinitis; asthma; atopic dermatitis.

Fig 1

Flowchart depicting the study enrollment. KCDC, Korea Centers for Disease Control.

Fig 2

Disposition of patients in the Korean nationwide cohort. AD, Atopic dermatitis; AR, allergic rhinitis.

Fig 3

Association of allergic diseases with the results of SARS-CoV-2 test (primary outcome) among 291,959 patients, and the association of allergic diseases with clinical outcomes of COVID-19 (secondary outcome) among 7,340 patients who tested positive for SARS-CoV-2. The severe clinical outcomes of COVID-19 comprised admission to the ICU, invasive ventilation, or death. NA, Not applicable/available. The x-axis indicates a log-scale.

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