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.