Allergen immunotherapy: present and future.

In this article the present and future of immunotherapy is discussed under four general headings: (1) present understanding of mechanisms of immunotherapy, (2) present status of clinical efficacy of immunotherapy, (3) changes/challenges of immunotherapy on the horizon, and (4) future of immunotherapy. The mechanisms of immunotherapy are well delineated and show that immunotherapy alters the natural course of allergic disease. There is a reduction in inflammation, nonspecific hyperresponsiveness, prevention of new sensitivities, and progression of allergic rhinitis to asthma. Further efficacy continues after cessation of immunotherapy. Complete asthma control does not occur with pharmacotherapy. There is a need to recognize that adding treatment for asthma's allergic component with immunotherapy may be the solution to achieving the unmet goals of asthma therapy. There are new developments and challenges to the role of immunotherapy on the horizon but, at present, subcutaneous immunotherapy is the specific allergen treatment of choice in the United States.