Antihistamines and epithelial cells

Antihistamines have long been utilized in the symptomatic management (antih istaminic effects) of allergic rhinitis and conjunctivitis. Investigation i nto the nonsedating second-generation antihistamines suggests that they als o possess antinflammatory activity, and may be useful in the management of inflammation associated with allergic airway disease. In vitro studies have shown that these antihistamines decrease the migration and activation of e osinophils and diminish the release of pro-inflammatory mediators from mast cells and basophils after induction by immunological and nonimmunological stimuli. In vivo studies have also demonstrated that these antihistamines d ecrease inflammatory cell infiltration in allergic airway disease, and medi ator release from mast cells and basophils. Epithelial cells, due to their spatial arrangement and predominance in the airways, play a pivotal role in the etiology of airway disease. There is evidence that antihistamines may modulate airway inflammation by influencing the activity of these airway ep ithelial cells. Studies have shown that expression of adhesion molecules on epithelial cells is decreased by second-generation antihistamines. Collect ively these studies suggest that second-generation Hi-histamine receptor an tagonists have potential use either as safe antiinflammatory alternatives t o corticosteroids or as rescue medication in combination with corticosteroi ds for the management of severe airway disease.