Prevalence of asthma, rhinoconjunctivitis and atopic eczema among Brazilian adolescents. Comparison between ISAAC phases I and III*1

Objective To compare the prevalence of asthma (A), rhinoconjunctivitis (R) and atopic eczema (AE) obtained in two different occasions, among adolescents from five Brazilian cities. Methods ISAAC's written questionnaire was applied to 13-14-year-old adolescents from five Brazilian cities (Curitiba, Porto Alegre, Recife, Salvador and Sao Paulo) in 1994/5 (Phase I) and 2002/3 (Phase III). "Have had wheezing in the last year" identified adolescents with A. The concomitant report of "nasal and ocular symptoms in the last year" identified the presence of R and "eczema in the last year evidenced in flexural areas" defined AE. Results The comparison of data obtained, showed that on Phase III: there was a significant reduction in the prevalence of A in Porto Alegre (24.7% × 18.2%) and Sao Paulo (23.3% × 18.7%). No significant differences were observed in Recife (19.7% × 19.1%), Salvador (27.1% × 24.6%) and Curitiba (18.4% × 18.9%). The prevalence of R increased significantly in Curitiba (14.1% × 17.2%) and Recife (11.3% × 14.5%). Significant changes did not occur in Salvador (25.0% × 24.4%), Sao Paulo (12.6% × 12.2%) and Porto Alegre (17.6% × 15.9%). There was a significant reduction in the prevalence of AE in Salvador (9.2% × 6.5%). In Recife (4.6% × 5.0%), Sao Paulo (3.7% × 3.6%), Curitiba (3.9% × 3.7%) and Porto Alegre (4.8% × 5.0%) the changes observed were not significant. Conclusions In Brazil, there is no homogeneous pattern in the prevalence of allergic diseases, comparing the prevalence in five cities (states' capitals) between ISAAC's phases I and III (7-8 years interval).