Change in prevalence of IgE sensitization and mean total IgE with age and cohort

Background: Cross-sectional studies show that the prevalence of IgE sensitization is lower in older age groups than younger age groups. This could reflect either a decrease in sensitization with aging or a higher prevalence of sensitization in more recent birth cohorts. Objective: To assess change in IgE sensitization and mean total IgE in young adults as they age. Methods: Serum specific IgE to common allergens and total IgE were measured on 2 occasions about 9 years apart in 6371 young adults living in 28 centers, mainly in Western Europe, who took part in the European Community Respiratory Health Survey II. Outcomes were analyzed by using generalized estimating equations, and adjustments were made for differences between laboratory measures on the 2 occasions. Results: Overall, there was no net change in the prevalence of sensitization to at least 1 of house dust mite, grass, or cat (net change per 10 years of follow-up, -0.1%; 95% CI, -1.7% to 1.5%), although there was a fall in mean total IgE (ratio of geometric mean total IgE, 0.86; 95% CI, 0.79 to 0.93). There was evidence that sensitization to at least 1 allergen was higher in more recent cohorts, and this was largely explained by a higher prevalence of sensitization to grass. Conclusion: The disease burden associated with IgE sensitization in adults, and particularly with IgE sensitization to grass, is likely to continue to increase for some time despite current evidence that the increase in allergy seen in children may have ceased.