The prevalence of asthma and atopy in schoolchildren from Porto Alegre, Brazil, has plateaued

SummaryObjectiveA significant increase in the prevalence of asthma and atopy was observed in epidemiological studies conducted in 1980, 1989 and 1998, with schoolchildren of Porto Alegre. The present study aims to determine changes in the prevalence of symptoms of current and lifetime asthma and also to document the prevalence of atopy in schoolchildren from a region of Porto Alegre.MethodsThis was a cross-sectional study in which schoolchildren from 5th to 8th grade (10-18 years), from four schools located in the same geographic area were interviewed. The questionnaire covered symptoms suggestive of lifetime or current asthma (at some point in life or in the last twelve months, respectively). In addition, skin tests were performed in a subset of 241 schoolchildren.Results964 students were interviewed from a total of 1195 registered. The prevalence of lifetime asthma symptoms was found to be 41.7%, symptoms of current asthma 14.9% and atopy 52.7%. Compared to previous studies, the prevalence of lifetime asthma and atopy has stabilized while the prevalence of current asthma fell from 22% to 14.9% (P < 0.001).ConclusionsIn the last decade the prevalence of atopy and lifetime asthma has plateaued, while the prevalence of current asthma fell.