Allergy immunotherapy for inhalant allergens: Strategies to improve efficacy

Background: Allergy immunotherapy (AIT), both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT), is an effective and safe treatment for allergic rhinitis and allergic asthma due to inhalant allergens. However, there are many variables in how it is administered. Objective: To review the evidence that suggests the optimum practices to enhance the efficacy of AIT. Methods: Articles that reported the results of various approaches to the practice of AIT and evidence-based guidelines were consulted for guidance on what approaches would enhance the efficacy of AIT. Results: Evidence is presented that supports optimum dosing for SCIT, a discussion of dosing with liquid SLIT, the management of the patient who is polyallergic, considerations in mixing allergen extracts, advantages and disadvantages of different up-dosing regimens with SCIT, the optimum duration of AIT, the comparative efficacy of SCIT and SLIT, and improving adherence to AIT. Also reviewed were two approaches, the use of adjuvants and of alternative routes of administration of currently available extracts, which may be useful in the future after further studies have defined their effectiveness. Conclusion: Although there is still controversy about some aspects of AIT, there is literature to support approaches that enhance the efficacy of both SCIT and SLIT.