Risk factors for systemic reactions to allergen immunotherapyIglesias-Cadarso, Alfredo; Hernández-Weigand, PilarCurrent Opinion in Allergy & Clinical Immunology: December 2011 - Volume 11 - Issue 6 - p 579–585 doi: 10.1097/ACI.0b013e32834c229e Immunotherapy and new treatments: Edited by Giovanni Passalacqua and Robert Bush Abstract Author Information Purpose of review: To update safety information regarding allergen-specific immunotherapy (ASIT) in clinical practice and highlight the risk factors associated with the adverse reactions, product and each dose. Recent findings: Efforts in recent years have focused on increasing our understanding of the efficacy and safety of ASIT, especially the sublingual variety (SLIT), in multicenter studies. Moreover, new Clinical Practice Guidelines (CPGs) and an international consensus concerning ASIT have been published recently. Although no deaths as a result of subcutaneous immunotherapy or SLIT have been reported in the last 2 years, systemic reactions mainly arising from administration errors still appear. Recent studies support the safety of new forms of specific immunotherapy. Summary: An understanding of the risk factors for each patient, product and dose, and the implementation of CPGs are the main factors that could improve the safety of ASIT. The standardization of all procedures for prescribing and administering ASIT, and the systematic collection of standardized safety data in a multicenter database (postmarketing surveillance), may be required to generate new information on the safety of ASIT. aAllergy Department, Hospital Puerta de Hierro – Majadahonda bENT Department, Hospital Clínico San Carlos, Madrid, Spain Correspondence to Alfredo Iglesias-Cadarso, Allergy Department, Hospital Puerta de Hierro – Majadahonda, C/Manuel de Falla 1, Majadahonda, 28222 Madrid, Spain Tel: +34 911917180; e-mail: firstname.lastname@example.org,email@example.com Copyright © 2011 Wolters Kluwer Health, Inc. All rights reserved.