Conclusion: The overall duration and reciprocity of the nasal cycle were not changed after allergen provocation. The duration of immediate response was 38 min, but the amplitude of the nasal cycle was increased significantly after allergen provocation.
Objective: Nasal airflow is asymmetrical and subjected to spontaneous reciprocal changes which are referred to as the nasal cycle. Limited information is available on how this is affected by allergens. The purpose of this study was to evaluate the effects of allergen provocation on the nasal cycle.
Materials and methods: This study was performed on 25 patients with allergic rhinitis and 25 subjects in a control group with no symptoms of allergic rhinitis. Acoustic rhinometry was used to test patients before and after allergen provocation. The patients underwent acoustic rhinometry at 15-min intervals for evaluation of nasal cycle and 3-min intervals for immediate response.
Results: With the allergic patients, 21 of the 25 patients (84.0%) showed a nasal cycle and they still had a nasal cycle after the allergen provocation. In the study on the changes in the immediate responses, the average recovery time was 38 min and the reduction rate of the non-patent side was higher than that of the patent side. Also, the average period of the nasal cycle was 153 min before the allergen provocation and 140 min on average after the allergen provocation; there were no statistical differences. The amplitude of each nasal cycle increased after allergen provocation and the difference had statistical meaning.