Prevalence of asthma, rhinitis and eczema in 6 - 7 years old students from the western districts of São Paulo City, using the standardized questionnaire of the "International Study of Asthma and Allergies in Childhood" (ISAAC)-phase IIIB

Abstract

The aims of the present work were the evaluation of allergic disease prevalence among 6 and 7 year-old students from the western districts of São Paulo city and the comparison of these data with those obtained in the International Study of Asthma and Allergies in Childhood (ISAAC) phase I, performed in the central-southern districts of São Paulo, using the ISAAC standardized written questionnaire.

Methods: 5,040 questionnaires were distributed and 3,312 were returned. Proportional differences were estimated by Chi square or Fisher exact tests. Odds Ratio and 95% confidence intervals between genders and allergic diseases were calculated. Values of p<0.05 were considered statistically significant.

Results: The corrected prevalences found were: asthma 24.4%, medical diagnosis of asthma 5.7%, rhinitis 25.7%, rhinoconjunctivitis 11.3%, medical diagnosis of rhinitis 20.0%, atopic eczema 9.2%. Significant associations between asthma and rhinitis (OR=3.3), asthma and eczema (OR=2.2), and rhinitis and eczema (OR=2.8) occurred. The male gender was prevalent regarding asthma and rhinitis. Compared to data from ISAAC phase I, higher asthma prevalence and severity, and lower values for rhinitis and eczema were observed in this study.

Conclusions: The present study evidenced high prevalences for asthma and rhinitis compared to the children's medical diagnosis. The male gender predominated in all positive responses regarding asthma and rhinitis. The most frequent associations observed were between asthma and rhinitis and asthma and eczema. In the western districts of São Paulo, a higher prevalence of asthma symptoms and severity and lower prevalences for rhinitis and eczema occurred compared to the central-southern districts of the city.