Rising prevalence of allergy to peanut in children: Data from 2 sequential cohorts.

Background: Allergy to peanut is common. However, it is not known whether the prevalence of sensitization and clinical allergy to peanut is increasing.
Objective: We sought to determine any change in the prevalence of peanut sensitization and reactivity in early childhood in 2 sequential cohorts in the same geographic area 6 years apart.
Methods: Of 2878 children born between September 1, 1994, and August 31, 1996, living on the Isle of Wight, 1273 completed questionnaires, and 1246 had skin prick tests at the age of 3 to 4 years. Those with positive skin prick test responses to peanut were subjected to oral peanut challenges, unless there was a history of immediate systemic reaction. These data were compared with information on sensitization and clinical allergy to peanut available from a previous cohort born in 1989 in the same geographic area.
Results: There was a 2-fold increase in reported peanut allergy (0.5 % [6/1218] to 1.0 % [13/1273]), but the difference was nonsignificant (P =.2). Peanut sensitization increased 3-fold, with 41 (3.3 %) of 1246 children sensitized in 1994 to 1996 compared with 11 (1.1 %) of 981 sensitized 6 years ago (P =.001). Of 41 sensitized children in the current study, 10 reported a convincing clinical reaction to peanut, and 8 had positive oral challenge results, giving an overall estimate of peanut allergy of 1.5% (18/1246).
Conclusions: Sensitization to peanut had increased between 1989 and 1994 to 1996. There was a strong but statistically nonsignificant trend for increase in reported peanut allergy.