Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 2 3 2003 09 15 165 168 2015 10 01 The prevalence of allergic disorders has increased markedly throughout the world over the past three decades. It seems probable that the increased prevalence is real because longitudinal studies have shown a rapid exponential increase in allergic disor¬ders. In order to determine the prevalence of type 1 allergy in patients with allergic disorders in Sistan-Blouchestan province, in the Southeast of Iran, patients referred to Immunology and Allergy Medical Center of Khatam Hospital during a 7-year period were studied. One thousand two hundred and eighty-six patients (554 males and 732 females), aged 2-79 years, had allergic disorders. The most frequent allergic disease was rhinitis, seen in 959 patients (74.57%). Also, 939 patients had a history of sinusitis (73.02%). Among the skin prick test(SPT)-positive patients, a positive prick test reaction to the house dust mites (89.74%), feathers (70.29%), and Aspergillus (65.08%) was most common, followed by Alternaria (57.39%), Cladosporium (47.12%), grasses (43.39%), trees (41.29%), Penicillium (39.19%), fruits (38.41%), and weeds (32.50%). Also, 30.33% of the subjects were sensitized to Hen's egg in the prick test, walnut (29.16%), cow's milk (21.46%), beef meat (19.21%), and hazel-nut (15.32%) accounting for other positive reactions. The prevalence of SPT-positive to common allergens is high among Iranian pa¬tients with allergic disorders. So, it should be recognized in the diagnosis of allergic diseases as well as in allergen-reduction programs. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/51 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/51/51