Patterns in the Development of Pediatric Allergy

Current knowledge of the epidemiology of allergic conditions is largely based on retrospective survey data, which often relies on caregiver or patient-reported data and is subject to recall bias. This study used an electronic health record-based cohort to evaluate patterns of pediatric allergic conditions.There were 218 485 children included from across the United States. Inclusion criteria were establishing care before 1 year of age and being observed for at least a 5-year period between 1999 and 2020. Patients were followed through 18 years of age.This was a retrospective cohort study utilizing the Comparative Effectiveness Research through Collaborative Electronic Reporting Consortium database. Patients with atopic dermatitis (AD), IgE-mediated food allergy (IgE-FA), asthma, allergic rhinitis (AR), and eosinophilic esophagitis (EoE) were identified using diagnosis codes and medication prescription data. For each disease entity, age at diagnosis, cumulative incidence, and potential comorbidities were reported.The peak age of incidence was 4 months for AD, 13 months for IgE-FA, 13 months for asthma, 26 months for AR, and 35 months for EoE. The cumulative incidence (a substitute for prevalence) was 10.3% for AD, 4.0% for IgE-FA, 20.1% for asthma, 19.7% for AR, and 0.11% for EoE. The IgE-FAs with the overall highest cumulative incidences were peanut (1.9%), egg (0.8%), and shellfish (0.6%). Asthma and AR were notably comorbid with one another, as well as with AD, IgE-FA, and EoE. Of children, 13.4% had ≥2 allergic conditions.The patterns of allergic disease reported in this nationwide electronic health record-based cohort continue to support the “atopic march,” with peak incidence of AD occurring first in infancy, followed by IgE-FA and then asthma. The cumulative incidence of IgE-FA was also on the lower end of previous reports. Allergic conditions were found to have high rates of comorbidity, supporting the notion that one allergic diagnosis should raise clinical suspicion for the possible development of another.Allergic diseases are common in children, but epidemiologic data has been largely patient reported through surveys. A sound understanding of epidemiology is vital to supporting clinical care and future research. Data from this EHR-based cohort bolsters prior knowledge regarding the progression of atopy and offers novel insight into the patterns of allergic childhood diseases.