ABSTRACT
In 1986, the British Committee for the Safety of Medicines officially reported 26 fatalities associated with SCIT (5). As a consequence, the risk-benefit ratio of immunotherapy was more critically questioned. The result was revision of the indications and implementation of additional safety measures, making the treatment impractical in some countries. The safety concerns with SCIT and resulting inconvenience stimulated the search for safer IT modalities, and the noninjection routes gained new interest. Although some of the adverse events (AEs) with SCIT can be avoided, others occur without explanation (6,7), contributing to the growth in interest of noninjection routes deemed to be safer. The first controlled trial with sublingual immunotherapy (SLIT) was published in 1986 (8). The earliest studies with SLIT were conflicting but an increasing number of positive studies were subsequently published. SLIT was mentioned in immunotherapy guidelines 10 years after the first SLIT trial (9), and in some subsequent guidelines (10,11). SLIT was categorized as a reasonable alternative to SCIT. Currently, SLIT is routinely used in several European countries, where standardized extracts for the relevant allergens are available. There is no FDA-approved SLIT allergen extract/ vaccine in the United States and therefore SLIT is not an approved treatment.
