Incidence rates of allergy diagnoses in the U.S. military health system after the COVID-19 pandemic.

Introduction: During the COVID-19 pandemic, exposures to environmental allergens and microorganisms were dramatically altered, potentially impacting the development and diagnosis of allergic conditions. Methods: We conducted a retrospective, repeated, monthly cross-sectional study examining monthly incidence rates of allergic diseases diagnosed before and throughout the first 3 years of the COVID-19 pandemic in individuals aged 0-64 years enrolled in the TRICARE Management Activity Military Health System (MHS) Data Repository (MDR). Allergic diseases were grouped into twelve categories. Rates of incident outcomes were calculated monthly and compared between subgroups and during the pre-pandemic year (March 1, 2019-February 29, 2020) and the first 3 years after the COVID-19 Pandemic beginning on March 1, 2020. Results: Allergy diagnoses of all twelve conditions assessed were lower during COVID-19 year 1 (incidence 430 per 100,000) compared with the pre-pandemic year (incidence 750 per 100,000). This reduction in allergic diagnoses during COVID-19 year 1 was statistically significant for all allergic diagnoses queried. During COVID-19 years 2 and 3, allergy diagnoses of all conditions, except for anaphylaxis and food protein induced enterocolitis syndrome (FPIES) remained lower compared with the pre-pandemic year. The decrease in allergic diagnoses was greater than the decrease in total MHS healthcare visits. Discussion: In the MHS, for the first 3 years of the COVID-19 pandemic, allergic diagnoses were lower than in year prior to the pandemic. This reduction cannot be fully explained by decreased healthcare utilization.