Association between allergic conditions and COVID-19 susceptibility and outcomes

BACKGROUND:The relationship between underlying type 2 inflammation and immune response to COVID-19 is unclear. OBJECTIVE:Assessing relationships between allergic conditions and COVID-19 susceptibility and outcomes. METHODS:In the Optum® database, adult patients with and without major allergic conditions (asthma, atopic dermatitis [AD], allergic rhinitis [AR], food allergy, anaphylaxis, eosinophilic esophagitis [EoE]) and patients with and without severe asthma/AD were identified. Adjusted incidence rate ratios (aIRR) for COVID-19 were compared among patients with vs without allergic conditions or severe asthma/AD vs non-severe asthma/AD during 4/1/2020-12/31/2020. Among patients with COVID-19, adjusted hazard ratios (aHR) of 30-day COVID-19-related hospitalization/all-cause mortality were estimated for the same comparisons during 4/1/2020-3/31/2022. 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 (1.12 [1.09, 1.15]) were associated with increased incidence of COVID-19. Among patients with COVID-19 (patients with [N = 261,076] and without allergic conditions [N = 1,098,135] were matched on age, sex, region, index month), having an allergic condition had minimal impact on 30-day COVID-19-related hospitalization/all-cause mortality (aHR [95% CI] 0.96 [0.95, 0.98]) but was associated with a lower risk of mortality (0.80 [0.78, 0.83]). Asthma was associated with a higher risk of COVID-19-related hospitalization/all-cause mortality vs non-asthma allergic conditions (aHR [95% CI], 1.27 [1.25, 1.30]). CONCLUSION:Allergic conditions were associated with an increased risk of receiving COVID-19 diagnosis but reduced mortality after infection.