Recognition and Frequency Determination of Common Allergens in Allergic Patients of Zanjan City by Skin Prick Test Ahmadiafshar A1, Sepehri S2, Moosavinasab SN3, Torabi SZ1 1 Dept of Pediatric, Ayat-ul-Alah Moosavi Hospital, Zanjan University of Medical Sciences, Zanjan, Iran 2 Zanjan University of Medical Sciences, Zanjan, Iran 3 Dept of Social Medicine, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Corresponding Author's Address: Dept of Pediatric, Ayat-ul-Alah Moosavi Hospital, Zanjan University of Medical Sciences, Zanjan, Iran E-mail: akefeh45@zums.ac.ir Received: 13 Jan, 2008 Accepted: 24 Nov, 2008 Background and Objective: Recognition of various environmental allergens is of great importance. Since contact with them may cause or accelerate sympotoms in allergic patients. Our purpose of this study was to determine sensitivity to common allergens by skin prick test. Materials and Methods: Patients with allergic rhinitis, asthma and atopic dermatitis referred to Allergy Clinic of Valie Asr Hospital of Zanjan City, 2003-2005, were submitted to skin prick test with a series of indoor, outdoor and food allergens. Results: Two hundred patients (111 females and 89 males) 4-60 years of age were recruited. Eighty three percent of subjects showed at least one positive skin prick test. The skin prick tests were positive for grass (Rye grass 41%), weed (pigweed 27%, Herb 21%), Tree (olive 22%, Ash 20%, Butirytis 19.5% ), Mites (D.P 16%, D.F 16%), Cockroach 14.5%, feather11%, Mold (Aspergillus 11.5%, Alternaria 7.5%), Food (Wheat 9%, Pepper7.5%, Egg 6.5%). Conclusion: According to the freguency of positive skin tests to pollens in our patients, it seems that avoiding contanct with these agents in related seasons, treatment ineluction, drug dose acceleration and desensitization procedures would be of great help in allergic patients.