Subcutaneous specific immunotherapy for seasonal allergic rhinitis: a review of treatment practices in the US and Europe

Background: Subcutaneous specific immunotherapy (SCIT) is claimed to be successful both in the US and Europe, yet treatment methodology differs. Methods: The authors review current literature surrounding guidelines and clinical trials in Europe and the US and contrast the treatment approach to SCIT for allergic rhinitis. Search methodology employs MEDLINE and PubMed, selecting articles on SCIT and allergic rhinitis, limited between 1990-2009. They focus on the safety and efficacy of vaccines, and the differences in formulations. Also mentioned are: standardization, new approaches in SCIT and sublingual immunotherapy (SLIT). Results: SCIT treatment differs in many respects regarding availability of SCIT products, regulatory controls, guidelines (e. g. multiple allergen vaccines in US, single allergen vaccines in Europe) and in location of formulation (US, clinician's office; Europe, manufacturers). Conclusions: SCIT is an effective and safe therapy, but major evidence for efficacy is provided from European studies of single allergen extract vaccines; these vaccines may gain more acceptance because of increasing regulatory approval and lower numbers of injections. The potential impact upon public health (e. g. arrest of the 'allergic march') should not be overlooked.