Data were analyzed from December 2020 to April 2024.<h4>Exposures</h4>Exposures included decade of birth, cohort type (population-based or high-risk), family history of asthma (mother, father, or sibling), birth order, gestational age at birth, delivery mode, breastfeeding, pet exposure, antibiotic use, environmental tobacco smoke exposure, allergic sensitization, peripheral blood eosinophil count, and total IgE.<h4>Main outcomes and measures</h4>Primary outcomes were AD phenotype, food allergy, allergic rhinitis, asthma, and wheeze. This evidence concerns the gene IGHE and Alzheimer disease.