The Trend of Change of Allergic Diseases over the Years: Three Repeated Surveys from 1994 to 2014

Background: Although it is known that there has been an increase in asthma and allergic diseases among school-aged children, results vary between countries. The aim of this study was to examine trends in the prevalence of these diseases in the city of Adana (south Turkey) over the last 20 years based on the results of 3 cross-sectional studies. Methods: Three cross-sectional surveys were performed 10 years apart in south Turkey. Here, we compare the surveys conducted among children between the ages of 6 and 14 years from 1994, 2004, and 2014. The participants were randomly chosen among children attending participating primary schools in Adana. The questionnaire in the first survey contained almost the same questions as the ISAAC. In the 2 latter surveys, we used the ISAAC questionnaire to investigate the prevalence of asthma and other allergic diseases. Results: A total of 2,334 children in 1994, 3,728 children in 2004, and 3,209 children in 2014 were included in the final analysis. The results showed a statistically significant increase in the prevalence of physician-diagnosed allergic diseases across the years, respectively: asthma (5, 4.6, and 8.9%), allergic rhinitis (8.8, 11.4, and 15.6%), and atopic dermatitis (5, 9.9, and 7%). In contrast, the prevalence of parent-reported current wheeze (16.2, 13.2%) decreased in the last 10 years. Conclusions: Our findings were consistent with the increased prevalence of childhood asthma and other allergic diseases. However, this pattern did not occur in respiratory symptoms.