Changes in unilateral nasal airflow in patients with seasonal allergic rhinitis measured in and out of season

Objective: Nasal congestion is a common complaint of patients suffering from seasonal allergic rhinitis yet there are very few investigations which have studied the objective changes in nasal airflow in and out of season. The aim of this study was to investigate the changes in nasal airflow in and out of season. Methods: In the present study unilateral nasal airflow was measured in and out of the pollen season in 13 patients with seasonal allergic rhinitis. Unilateral nasal airflow was measured using posterior rhinomanometry at an inspiratory reference pressure of 75 Pa. Results: There was no significant difference between median total nasal airflow in season (325 cm3/s) and out of season (324 cm3/s) (P=0.15, n=13) yet there was a significant difference between maximum unilateral airflow in season (278 cm3/s) and out of season (234 cm3/s) (P=0.007, n=26). Conclusion: The results of the present study indicate that although patients with seasonal allergic rhinitis may experience a sensation of nasal congestion at the start of the pollen season there is little or no change in total nasal airflow and unilateral nasal airflow may be increased.