Evaluation of Nasal Obstruction in Patients with Perennial Allergic Rhinitis Using Acoustic Rhinometry.

The evaluation of nasal obstruction is important for the treatment of perennial allergic rhinitis. Although, nasal resistance induced by rhinomanometry is useful, several authors have reported that nasal resistance is not correlated with the sensation of nasal obstruction.Acoustic rhinometry was introduced by Hilberg et. al. (1989) to assess the geometry of nasal cavity. The method, based on sound reflection analysis provides an estimate of the cross-sectional area of the nasal cavity as a function of the distance from the nostril. Recently, acoustic rhinometry has become popular in our country. The aim of this study was to evaluate changes in the nasal mucosa of patients with perennial allergic rhinitis and in normal subjects and to investigate the benefits of acoustic rhinometry.Ten normal subjects and 10 patients with perennial allergic rhinitis were measured by acoustic rhinometry before and after administration of a topical decongestant using an acoustic rhinometer (RHIN2100 SRE co. Denmark). Changes in the nasal volume (0.8-4.0cm) (0-7.0cm) and cross-sectional area (c-notch) were greater in patients than in normal subjects. However, the nasal volume and cross-sectional area in patients with perennial allergic rhinitis were the same as in normal subjects.These results suggest that the nasal mucosa of patients with perennial allergic rhinitis is more swollen than that of normal subjects. Moreover, measurements of nasal volume and nasal cross-sectional area are able to define the structure of the nasal cavity. These values can be utilized to evaluate baseline values and improvements when medications are administered.In conclusion, acoustic rhinometry is potentially useful for evaluating nasal physiology, especially in cases of allergic rhinitis.