The Effects of Topically Administered Methacholine on the Nasal Patency as Assessed by Acoustic Rhinometry

ABSTRACT

The aim of this study was to evaluate the effect of topical methacholine on the nasal mucosa in allergic rhinitis and nonallergic control group, particularly in terms of nasal patency. The study population consisted of 32 adults with no nasal disorders and 22 patients with nasal allergy, and their age ranged from 18 to 42. Increasing concentrations of methacholine ranging from 0.125% to 25% were sprayed on both nasal cavities of the study subjects. The minimal cross sectional area and the nasal cavity volume at each concentration were measured using acoustic rhinometry. The overall incidence of methacholine responsiveness was 56%. The allergic group did not show a significantly higher incidence of methacholine responsiveness compared to the control group. The incidence and the pattern of methacholine responsiveness was not bilaterally symmetric on both sides of the nasal cavities. The results of this study indicate that, both in allergic and control group, topical methacholine stimulation resulted in decreased nasal patency only in a subset of the population.