CHANGES OF THE NASAL CYCLE IN PATIENTS WITH ACUTE UPPER RESPIRATORY TRACT INFECTION AND SEASONAL NASAL ALLERGY

Abstract

It is well known that unilateral nasal patency spontaneously changes over time in human beings, often referred to as 'nasal cycle', which was first reported over 100 years ago. However, the study of the nasal cycle has made slow progress with the major hindrance being a lack of numerical parameters which could precisely describe the changes of nasal patency over time. In this study, we investigated the effects of acute upper respiratory tract infection and seasonal allergic rhinitis on the nasal cycle using two numerical parameters of the correlation coefficient between unilateral nasal resistance (r) and the airflow distribution ratio between the two nasal airways (ADR).
Ten subjects (5 males and 5 females, aged 19-38 years) with acute upper respiratory tract infection (URTI) and thirteen subjects (5 males and 8 females, aged 19-33 years) with seasonal allergic rhinitis (hay fever) were recruited for the study, which involved serial measurements of unilateral nasal airway resistance using the technique of posterior rhinomanometry. In subjects with URTI, unilateral nasal resistance was measured hourly over a 6 hour period on one day when subjects had symptoms of URTI and 6-8 weeks later when they were healthy. In subjects with hay fever, unilateral nasal resistance was measured hourly over a 7 hour period in and out of the allergic season.
The nasal cycle of subjects with URTI was similar to that of normal human beings. The result indicates that the nasal cycle was not so much affected by URTI. On the other hand, the nasal cycle of subjects with hay fever not only in season but also out of season differed considerably from that of normal human beings and subjects with URTI. The results indicate that the nasal cycle may be affected by a disorder of the autonomic nervous system and/or by permanent changes of the nasal mucous membrane due to hay fever.