Abstract
The use of allergen immunotherapy (AIT) in Brazil has specific regional conditions owing to the pattern of allergen sensitization, as well as to genetic, socioeconomic, and cultural characteristics. This review article aims to discuss the clinical practice of AIT by the subcutaneous or sublingual route in Brazil, addressing the possibilities of transition between these forms of administration. A systematic review using the PubMed and Cochrane databases was performed, and the websites of major allergy and immunology organizations were consulted. Knowledge of the mechanism of action of subcutaneous immunotherapy and sublingual immunotherapy, together with Brazilian real-life experience, allowed us to establish recommendations regarding switching routes of AIT administration in selected cases. Careful analysis of each clinical situation is necessary to perform the transition between subcutaneous and sublingual allergen immunotherapy.