New therapeutic approaches to the treatment of nasal allergy: Antiinflammatory effects of H(1) receptor antagonists.

Histamine is recognized as an important mediator of allergic rhinitis. In addition to the role it plays in the immediate-phase reaction of nasal allergy, histamine may play an important role in the late-phase reaction and protracted allergic inflammation. Histamine induces the synthesis or secretion of proinflammatory cytokines and the expression of adhesion molecules. Besides their traditional effects via H(1) receptor antagonism, antihistamines have been reported to possess multiple antiinflammatory effects. Continuous use of antihistamines may reduce the level of minimal persistent inflammation of nasal mucosa in allergy. Treatment of allergic rhinitis using antihistamines could contribute to the improvement in coexisting allergic inflammation of the lower airways. (c) 2001 Prous Science. All rights reserved.