Allergen immunotherapy for respiratory allergies in clinical practice: A comprehensive review

Allergen-specific immunotherapy (AIT) is the only treatment that modifies the underlying pathophysiology of IgE-mediated allergic diseases. Evidence shows the efficacy in achieving better control of the symptoms and reduction in medication use in patients with allergic rhinoconjunctivitis and/or asthma. It should be used in association with proper pharmacotherapy for at least three years. The benefits are sustained for several years after discontinuation of treatment. Moreover, it may prevent the development of new sensitization and progression of disease from allergic rhinitis to asthma in children. The favorable efficacy of AIT is associate to the appropriate selection of patients, allergen extracts, adherence, and duration of treatment. Safety during AIT is another concerning issue. AIT has an acceptable safety profile if administered under the appropriate circumstances. Future studies investigating the prescription, efficacy, and safety need to be developed. The new application routes, use of adjuvants, modification of allergens, and use of biologics are currently under evaluation. Moreover, there is an urgent need for real-world data in developing countries regarding the cost-effectiveness analysis, and optimization of AIT schedules and products, so that clinical practice and implementation of AIT for respiratory allergic diseases can be effective and safe.