Allergen immunotherapy: routes, safety, efficacy, and mode of action

Allergic rhinitis, allergic conjunctivitis, and allergic asthma have been steadily increasing in prevalence in recent years. These allergic diseases have a major impact on quality of life and are a major economic burden in the US. Although allergen avoidance and pharmacotherapy are currently the mainstays of therapy, they are not always successful in treating patients' symptoms effectively. If a patient fails allergen avoidance and medical therapy, immunotherapy may be indicated. Furthermore, immunotherapy is the only therapy that may change the course of the disease and induce long-term remission. Though subcutaneous administration has been the standard route for immunotherapy for many decades, there are several other routes of administration that have been and are currently being studied. The goal of utilizing alternative routes of immunotherapy is to improve safety without decreasing the efficacy of treatment. This paper will review the novel routes of immunotherapy, including sublingual, oral, local nasal, epicutaneous, and intralymphatic.