The prevalence, natural history and time trends of peanut allergy over the first 10 years of life in two cohorts born in the same geographical location 12 years apart.

Background: The aim of this study was to explore the natural history of peanut allergy in childhood in two birth cohorts from the same geographical region in the South of England.

Methods: The FAIR birth cohort was established on the Isle of Wight (UK) between 2001 and 2002 (n = 969). Children were followed up prospectively, skin prick tested (SPT) to peanut allergens at 1, 2, 3 and 10 years and food challenges performed. The Isle of Wight (IOW) birth cohort was established in 1989 (n = 1456). SPTs were performed at 1, 2, 4 and 10 years. Peanut allergy was based on positive SPT and a good clinical history.

Results: In the FAIR cohort, the prevalence of sensitization to peanut was 0.4%, 2.0%, 2.0% and 2.4% at 1, 2, 3 and 10 years, respectively. At 10 years of age, 12 of 828 (1.5%) children were diagnosed with peanut allergy. One child (8%) outgrew her peanut allergy between 3 and 10 years and two children (15%) presented with new onset peanut allergy. Over the first 10 years of life, 13 of 934 (1.4%) children were diagnosed with peanut allergy. In the IOW cohort, 6 of 1034 (0.58%) were diagnosed with peanut allergy at 10 years. We found no significant differences between the FAIR and the IOW birth cohort for any of the time points studied.

Conclusion: Peanut allergy appears to be stable over the first 10 years of life in our cohorts. There was no significant difference in peanut sensitization or clinical peanut allergy between 1989 and 2001.