Scientific Study

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.