Relationship Between Nasal Cycle, Nasal Symptoms and Nasal Cytology

Background: The nasal cycle is the spontaneous congestion and decongestion of nasal mucosa that happens during the day. Classically, 4 types of nasal cycle patterns have been described: (1) classic, (2) parallel, (3) irregular, and (4) acyclic. Hypothalamus has been considered as the central regulator even if several external factors may influence its activity. Objective: The aim of the study was to evaluate the presence of a correlation between nasal cycle pattern, nasal cytology and nasal symptoms. Methods: Thirty healthy volunteers have been enrolled in the study. All subjects completed a Sino-Nasal Outcome Test-22 questionnaire and a Visual Analog Scale (VAS) for nasal obstruction. The nasal cycle was studied by means of peak nasal inspiratory flow. Nasal cytology has been used to evaluate the presence of local nasal inflammation. Results: Nineteen subjects showed a parallel nasal cycle pattern, while 11 showed a regular one. A parallel pattern was present in 60% of asymptomatic subjects and in 67% of the symptomatic one (P = 1). VAS for nasal obstruction did not show a significant difference between the 2 patterns of the nasal cycle (P =.398). Seventeen subjects had a normal rhinocytogram, while 13 volunteers showed a neutrophilic rhinitis; 53.8% of the subjects with a neutrophilic rhinitis showed a parallel pattern, while the remaining 46.2% had a regular one. In the case of a normal cytology, 70.6% of the volunteers had a parallel pattern and 29.4% had a regular one. Differences between the 2 groups were not statistically significant (P =.575). Conclusion: Rhinitis with neutrophils seems to not influence the nasal cycle pattern. Based on the present results, the pattern of nasal cycle does not influence subjective nasal obstruction sensation.