[Allergen-specific immunotherapy or desensitization].

Allergen-specific immunotherapy or desensitization represents an etiological treatment option for patients with allergic respiratory diseases. First introduced in 1911, it was widely disparaged until its mechanism of action was better understood and its efficacy on both allergic rhinoconjunctivitis and allergic asthma was demonstrated in double-blind placebo-controlled studies. Its indications are now widely agreed and practical rules have been established. Several factors have contributed to its increasing use in patients with respiratory allergies, including better-quality allergen extracts, better understanding of the mechanism of action, the introduction of oral tablet forms, and rationalization of prescriptions. Specific immunotherapy can benefit patients with severe allergic respiratory diseases in whom pharmacological treatment is ineffective or poorly accepted. Further well-designed and strictly conducted randomized trials in adults and children with allergic rhinitis and asthma are needed, using patient-important endpoints. More information is also needed on patient selection, the treatment duration, and dosing schedules.