RESUMO
BACKGROUND: Allergic respiratory diseases such as asthma and allergic rhinitis have increased considerably in the last decades. OBJECTIVE: The present study estimates prevalence trends of asthma, allergic rhinitis and pollinosis in the population of a city of Southern Brazil, without restriction of age, from 2011 to 2018, using the ISAAC standardized questionnaire. METHODS: Data was collected from March to June of 2011 and during the same months in 2018, in order to verify trends in the prevalence of these allergic conditions. The total sample consisted of 3132 individuals of both sexes living in the municipality of Santo Ângelo, in the state of Rio Grande do Sul, Brazil. RESULTS: No differences were observed in the prevalence of asthma diagnosis (15.1% in 2011 and 13.8% in 2018), however the prevalence of current wheeze was significantly reduced from 24.7% in 2011 to 21.2% in 2018 (p<0.05). Regarding allergic conditions in 2011 and in 2018, a significant reduction was observed (p<0.001) in reported current rhinitis (63.3% vs. 50.5%), rhinoconjunctivitis (48.9% vs. 38.8%), hay fever (52.0% vs. 43.3%), and pollinosis (29.0% vs 17.0%). Moreover, we observed an inverse relation between age and rhinoconjunctivitis and hay fever, and all symptoms were more frequent in females. Rhinoconjunctivitis and hay fever, as well as current rhinitis and pollinosis were highly prevalent among 30-39 years-old individuals, whereas current wheeze affected mainly the age group 10-19 years-old. CONCLUSION: While the prevalence of asthma remained similar after seven years, allergic rhinitis and pollinosis declined between 2011 and 2018.