Antihistamines: topical vs oral administration

The pathogenesis of allergic rhinitis is complex, involving not only histamine and mast cell-derived tryptase, but also eosinophil- and neutrophil-derived mediators, cytokines, and intercellular cell adhesion molecules (ICAM-1). It is surprising that antihistamines, which block only one component of the process, have proved so effective in the management of allergic rhinitis. Research has therefore focused on whether antihistamines have...