Nasal rinsing with an atomized spray improves mucociliary clearance and clinical symptoms during peak grass pollen season

Background: Nasal rinsing with an atomizer spray was found to be effective in the treatment of allergic rhinitis. Two parameters express the nasal functions: (1) mucociliary clearance (MCC), and (2) the pH and its stability. MCC is the main factor that defines the time of pollen transition on the nasal mucosa and, therefore, the amount of the allergen glycoprotein elution. Objectives: We hypothesized that the nasal wash efficacy could be due to the reduction of contact time of the grass pollen on the nasal mucosa (improving MCC). Methods: Forty patients with seasonal grass pollen oculorhinitis were randomized in two groups: 20 received three times daily nasal rinsing with hypertonic solution buffered to pH 6.1, before and during the peak pollen season in 2015 (active group), and another 20 patients were allocated to the control group and received no nasal treatment. The daily symptoms score and the use of oral antihistamines when required were evaluated during the grass pollen peak season. All the patients completed the study. Results: In comparison with the control group, in the active group, a significant decrease of both nasal symptoms (p = 0.01) and consumption of antihistamines (p = 0.035) was found. Furthermore, the MCC was significantly worse (p = 0.011) only in the control group. Conclusion: The nasal treatment maintained the efficiency of the MCC in the patients in the active group, who showed a significant reduction of symptoms and medication score. The MCC decreased the transit time of the pollen on the nasal mucosa, which favored an elution of the allergenic proteins.