The Incidence Rate of Atopic Diseases and Their Relation With Birth Order and Parent Age

The prevalence of atopic diseases had been increased significantly in recent decades. It seems that genetic predispostion accompanied with environmental factors play a considerable role in incidence of atopic diseases. The aim of this study was to evaluate the incidence rate of atopic diseases (asthma, rhinitis, conjunctivitis and atopic dermatitis) in Sanandaj and their relation with birth order and parental age at the date of birth. In this study Sanandaj was divided into three main regions according to the population and socioeconomic situation. The statistical population was 3500 men (age=16 to 26 years). Data was collected by trained interns and nurses in a questionnair, then encoded and analyzed by SPSS-win software. Of 3500 examined samples the frequency involvement of intrinsic asthma, seasonal asthma and atopic dermatitis were 2.1%, 4.3% and 14.5% respectively.The frequency of rhinitis or conjunctivitis (or both) was 17.9%. High birth order had a decreasing effect on seasonal asthma (P<0.05) and significantly increased prevalence of atopic dermatitis (paternal age at birth time showed the same results). Increased maternal age had decreasing effect on prevalence of seasonal asthma (P<0.04). This study showed that the prevalence of atopic diseases in studied populution was as high as the rate seen in developed countries. Regarding the result of this study with the exception of atopic dermatitis which needs further studies, birth order and parental age had a decreasing effects on other atopic diseases.