Objective: The objective of this study was to evaluate nasal mucosal swelling with acoustic rhinometry in subjects with asthma and in healthy controls.
Methods: We examined 184 individuals with asthma and compared with 156 randomly selected controls outside the pollen season, where 144 subjects in the asthma group and 80 controls had a previous history of non-infectious rhinitis (NIR). Nasal mucosal swelling was assessed with acoustic rhinometry before and after nasal decongestion with oxymetazoline and was analysed for the crosssectional area (4cm from the nostril) and the volume between 3.3 and 4cm from the nostril. Symptom scores for nasal blockage, secretion, itching and sneezing were assessed on a 0-10 visual analogue scale as well as peak nasal inspiratory flow and spirometry.
Results: Before decongestion there was a decrease in the cross-sectional area at 4 cm (1.32 cm2 vs. 1.59 cm2, mean left + right P = 0.04) and in the volume (1.70 vs. 1.91 cm3 P = 0.03) in the asthma group compared with healthy controls. After decongestion there were no significant differences in cross-sectional area at 4cm (1.66 vs. 1.73cm2 P=0.32) or volume (2.12 vs. 2.24cm3 P=0.32). Combined nasal symptom scores were higher in the asthma group (1.8 vs. 0.8, P=0.0001) and peak nasal inspiratory flow was lower (119 vs. 124 L/min, P = 0.38) than the healthy controls. FEV1 (% predicted) was also lower in asthma group (84 vs. 93% P < 0.0001).
Conclusion: We have been able to demonstrate an increased nasal mucosal swelling in a population sample of persons with asthma compared to healthy controls. These data support previous reports of a generalized airway inflammation in patients with asthma and suggest that acoustic rhinometry can be used to monitor the nasal mucosal swelling in these patients.