During puberty, both genders have an increase in the incidence of atopy (number of new positive skin prick tests (SPT)). We examined changes in the magnitude of an individual's SPT response to selected allergens (Grass (G), Cat (C) and Mite (M)) during adolescence.

We studied 1037 cohort study members, born in Dunedin, New Zealand between 04/1972, and 03/1973. Those individuals with SPT results for G,C,M allergens at both 13 and 21 years of age (646 individuals, 51.7% male) were included in this analysis. The change in the sum of the wheal response to these 3 allergens was compared within individuals by sex.

For the 11 allergens tested, the prevalence of any positive SPT (wheal 2mm. > negative control) increased in males from 58.0% at age 13 to 68.3% by age 21 (p<0.001), and from 37.5% to 63.5% in females (p<0.001). The sum of G,C,M accounted for (on average) 80% of the sum total wheal response for all 11 allergens. In study members with a positive SPT at age 13, female mean G,C,M SPT increased by 11.6 mm. (7.4 mm. at 13 years to 19.1 mm. at age 21; p<0.001, t-test) and males by 11.6 mm (8.8 mm. to 20.4 mm.; p<0.001). Histamine wheal size did not increase. The increase in wheal size over puberty was not significantly different between sexes (p=0.96).

In addition to acquiring new SPT, both sexes increased SPT wheal response to 3 common allergens. No differences between sexes in change in wheal size over puberty were found.