Prevalence and severity of allergic rhinitis among children of Tehran and Rasht: ISAAC study Phase III

ABSTRACT

Atopic disorders, for example atopic rhinitis, have had an incremental global trend. Epidemiological studies performed around the world have shown conflicting results; therefore, finding the accurate frequency of this disorder requires running a uniform and standard study. The aim of this study, as a part of International Study of Asthma and Allergy in Childhood [ISAAC], was to define and compare the prevalence of allergic rhinitis among 6-7 and 13-14 year old children of Tehran and Rasht during the years 2001-2002. This cross sectional-analytical study was performed during the years 2001-2002 in 63 elementary and 22 middle schools of Rasht and 51 elementary and 21 middle schools of Tehran, which were selected by cluster randomization of all schools in both cities. A total of 6145 children of Rasht and 6845 children of Tehran were enrolled into our study among which 54% were male and 48% were female in Rasht and Tehran, respectively. 3065 [50.5%] of Rasht students and 3015 [49.1%] of Tehran students were 6-7 years old and the remaining were 13-14 years old. The prevalence of rhinitis along with conjunctivitis was 4-5 times higher during a one year period among Tehran students. History of allergic rhinitis showed no significant difference between students of the two cities and was more prevalent among older children. Amongst the entire students, allergic rhinitis and rhino-conjunctivitis were more prevalent during January and February in Tehran, and April and May in Rasht. Prevalence of recent allergic rhinitis and rhino-conjunctivitis has been higher among Tehran students compared to students of Rasht, which demands for further and more precise evaluation