The Prevalence of Asthma, Allergic Rhinitis and Eczema in North of Iran: the International Study of Asthma and Allergies in Childhood (ISAAC)

Asthma, allergic rhinitis and eczema as a common chronic disorder in childhood, has many epidemiologic variations in different geographic areas. Uniform and standard epidemiologic researches are able to clear and modify scientific questions in this field. We carried out this study to determine the prevalence and intensity of pediatric allergic disease in our region. This analytical-cross sectional study was performed on 2 groups of children; the first group aged 6-7 years (n=3240) and the second group aged 12-14 years (n=3254) during 2002-03. According to ISAAC programming, sample size consisted of 3000 children in each group. From all students 99.3% of primary students and 88.8% of guidance students entered into study. Data was gathered by ISAAC first phase questionnaire and analyzed by SPSS 10 and Chi square test. The 12-month prevalence rates of symptoms were as follow: wheezing 16.8% and 21.7%, allergic rhinitis symptoms 14.5% and 19.9% and atopic dermatitis symptoms 4.5% and 8.2%, for younger and older age group, respectively. The prevalence of wheezing and current wheeze did not show differences according to sex (P>0.05) but it was significantly higher in students of guidance school (P<0.05). The prevalence of previous history of asthma, speech disorders, wheezing after physical exercises and dry cough at night, rhinoconjuntivitis, recurrent rhinitis, eczema with pruritus, recurrent lesions and history of eczema was significantly higher in boys and in students of guidance school (P<0.05). The prevalence of flexor lesion did not show a significant difference according to age (P>0.05) but in boys it was higher than in the girls (P<0.05). According to our findings asthma, allergic rhinitis and eczema have a moderate prevalence in this region of our country.