(106) Impact of allergic conditions on COVID-19 susceptibility and outcomes

Background: Several risk factors for SARS-CoV-2 infection or COVID-19-related severe outcomes were identified but the relationship between type 2 inflammation and immune response to COVID-19 has not been fully elucidated.

Objectives: To assess impact of allergic conditions, individually and overall, and underlying severity of the allergic condition on susceptibility to COVID-19 and severe COVID-19 outcomes.

Methods: In the Optum claims database, adults with and without allergic conditions (ie, asthma, atopic dermatitis [AD], allergic rhinitis [AR], food allergy, anaphylaxis, eosinophilic esophagitis [EoE]) and patients with and without severe asthma/AD (based on treatments received) were identified. Adjusted incidence rate ratios (aIRR) for the first SARS-CoV-2 infection from 4/1/2020–12/31/2020 (to avoid confounding effects of COVID-19 vaccines) were estimated using Poisson regression, adjusting for demographics, comorbidities, and healthcare resource utilization. We identified the first COVID-19 diagnosis (index date) from 4/1/2020–3/31/2022; patients with allergic conditions were then matched without replacement to up to 5 patients without on age, sex, region, and index month. Adjusted hazard ratios (aHR) of 30-day COVID-19-related hospitalization/all-cause mortality were estimated using Cox regression for the same comparisons.

Results: Patients with (N=1,273,231; asthma, 47.2%; AD, 1.5%; AR, 58.6%; food allergy, 5.1%; anaphylaxis, 4.1%; EoE, 0.9%) and without allergic conditions (N=2,278,571) were identified. Allergic conditions (aIRR [95% CI] 1.22 [1.21, 1.24]) and asthma severity (aIRR 1.12 [1.09, 1.15]) were positively associated with COVID-19 incidence. Among patients with COVID-19 (N=261,076 with and N=1,098,135 without allergic conditions), having an allergic condition had minimal impact on 30-day COVID-19-related hospitalization/all-cause mortality (aHR 0.96 [0.95, 0.98]) but was associated with a lower risk of mortality (aHR 0.80 [0.78, 0.83]). Asthma was associated with a higher risk of COVID-19-related hospitalization/all-cause mortality relative to non-asthma allergic conditions (aHR 1.27 [1.25, 1.30]), but a similar risk of mortality (aHR 0.97, [0.92, 1.02]). Severity of allergic conditions was associated with a higher risk of COVID-19-related hospitalization/all-cause mortality (aHR 1.10 [1.08, 1.13]).

Conclusions: Allergic conditions were associated with an increased risk of COVID-19 but reduced mortality. Future studies should seek to elucidate if these findings are driven by more aggressive patient management or a skewed immune response that favors Th2 over Th1 in these patients.