Effect of topical applications of budesonide and azelastine on nasal symptoms, eosinophil count and mediator release in atopic patients after nasal allergen challenge during the pollen season.

We studied the activity of a topical form of a corticosteroid (budesonide) and an antihistamine (azelastine) in the treatment of seasonal allergic rhinitis by including an assessment of mediator concentrations and the percentage of eosinophils in the nasal secretions before and after the treatment. Nasal allergen challenge (NAC) during the season was performed to mimic an acute attack of allergic rhinitis and to objectively evaluate the effect of the drugs on the early-phase reaction. The study compared in a randomized way (2 parallel groups) the effect of budesonide (Rhinocort Aqua) and azelastine (Allergodil nasal spray) in a group of 14 patients during the pollen season. The study showed that azelastine significantly reduced sneezing, total nasal resistance and increased nasal airflow even when significant increases in histamine, tryptase and leukotriene C4 (LTC4) concentrations in nasal secretions were evidenced immediately after NAC. Budesonide showed a strong (p<0.05) decrease in infiltration and activation of eosinophils, and on tryptase and LTC4 release after NAC. These effects (not for LTC4) lasted at least for 1 week after therapy. Azelastine is a powerful topical antihistamine, while budesonide appears to be a potent long-acting anti-inflammatory agent.