Background: Allergen immunotherapy has been reported to be effective in reducing allergic symptoms and drug consumption in cases of respiratory allergy. However, some concerns still exist about the relative safety of allergen immunotherapy. This form of therapy has a potential risk of serious systemic reactions.Objective: To evaluate the frequency of systemic reactions due to subcutaneous allergen immunotherapy in Iraq and to identify factors associated with increased risk of adverse systemic reaction. Methods:From January 2000 to December 2008, we selected 693 patients with allergic rhinitis and asthma to receive subcutaneous specific immunotherapy. Prospective immunotherapy safety was evaluated by recording postinjection adverse effects. The adverse reaction observed during the administration of subcutaneous immunotherapy within a period of 9 years (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008), was analyzed in this study.Result: Data were obtained from 693 patients who received subcutaneous immunotherapy (SCIT). The mean number of skin tests positivity and number of injections were significantly higher in systemic reaction group compared to negative systemic reaction group. During the study period, a total of 39281 injections were administered to 693 patients. Of the 693 patients, 82 (11.8%) had systemic reaction, with an incidence of 2.1/1000 injection. Sixty nine of the 82 systemic reaction (84%) developed in the build up phase, versus 13 (16%) in the maintenance phase (p<0.0001), with respect to reaction time, 47 (57%) of the systemic reaction were immediate (within 30 minutes respect to reaction time), and 35 (43%) were delayed. There were higher significant influences of polysensitisation, age, asthma, combination of asthma and allergic rhinitis, type of allergen, and indoor allergens on the development of systemic adverse reactions to subcutaneous immunotherapy. Conclusion:The present study suggests that SCIT was a safe treatment with a low risk to elicit severe systemic reaction, in which no fatality was observed. Furthermore, this study indicated that mold, HDM, asthma, presence of asthma and allergic rhinitis (AR), polysensitisation, and indoor allergens sensitization were a risk factors contributing to systemic reactions. consents were obtained from all patients (or their parents for children) before the initiation of immunotherapy and the guidelines were followed to monitor patients during allergen extract injection. Systemic Adverse Reaction to Specific ImmunotherapyThe adverse reaction observed during the administration of subcutaneous immunotherapy within a period of 9 years (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008), was analyzed in this study. Demographic and clinical data and peak expiratory flow before and after injection were recorded by the investigators on a standardized form. Immunotherapy scheduleImmunotherapy was given in term of conventional schedule. Conventional Immunotherapy build-up was typically given as injection per week until the maintenance dose wa...