Specific immunotherapy in grass pollen allergy.

Since its description by noon in 1911, desensitization, or allergen specific immunotherapy (SIT), has been largely used in respiratory allergic diseases treatment. It remains the only etiologic treatment for allergic diseases. The development of the sublingual route and new forms of medication, as an alternative to subcutaneous injection, has led to large scale clinical trials. Many of them had been performed with allergen tablets, particularly in the field of pollen allergy. These studies have confirmed that SIT is efficient in reducing all respiratory allergic symptoms. Data on long-term benefits and sustained efficacy after stopping treatment have also been published. These show an impact on natural history of allergic disease, in particular, a reduction in the risk of asthma in desensitized rhinitic subjects and in the acquisition of new sensitivities. The basic mechanisms of immunotherapy are becoming better understood and allow us to envisage improvements in this therapeutic method in the future. The sublingual route appears to be safer with a better safety profile. This may lead to an extension of allergen specific immunotherapy indications in patients with respiratory allergic diseases.