Allergen immunotherapy (AIT) is currently the only available disease-modifying and aetiological treatment of IgE-mediated diseases. Sublingual allergen immunotherapy (SLIT) constitutes the preferred route of administration of AIT for respiratory allergies in Europe. Recently it has also been approved in the US. Further applications are currently under evaluation, such as IgE-mediated food allergy and IgE-mediated atopic dermatitis. The SLIT safety profile is overall favourable, although local adverse events, usually mild, are described. Most of the meta-analyses confirmed the efficacy of SLIT in reducing symptoms and medication intake in children with allergic diseases. AIT, as an immune-modulating treatment, can modify the natural history of the allergic diseases: reduction of the risk of development of asthma and bronchial hyperreactivity in patients with allergic rhinitis, and reduction of the onset of new sensitizations. A great interest is now devoted to the preventive effects of AIT and, consequently, to the optimal time of initiation.
Keywords: allergen-specific immunotherapy; efficacy of SLIT; safety of SLIT; sublingual immunotherapy (SLIT).