Mechanisms of intranasal steroids in the management of upper respiratory allergic diseases.

Abstract

Intranasal steroids have proved to be the most effective class of drugs in reducing the symptoms of allergic rhinitis. This clinical response reflects the broad anti-inflammatory activity that has been demonstrated for corticosteroids. Single doses of topical corticosteroids administered before nasal allergen challenge block the late-phase reaction, whereas repeated dosing with intranasal steroids blocks both the early and the late response, as well as the priming phenomenon. Nasal inflammation is accomplished through a number of effector cells and mechanisms, which in turn are produced by director cells through the release of cytokines and chemokines. The anti-inflammatory action of corticosteroids is largely effected through blocking the synthesis and release of these cytokines/chemokines.