Sense of smell in allergic and nonallergic rhinitis

Abstract

Hyposmia is a fairly common complaint in patients with long-continuing allergic or nonallergic rhinitis. Other factors such as aging, smoking, or nasal surgery may affect olfaction, but these have been little studied in rhinitis-related hyposmia. The purpose of this study was to measure and compare olfactory thresholds in 105 rhinitis patients and 104 healthy controls and to analyze possible relationships between the sense of smell and rhinitis, age, sex, smoking, prick-test results, nasal resistance, and history of nasal or paranasal surgery. The olfactory threshold was assessed with a commercially available kit of squeeze-bottle pairs. The most important variables associated with the sense of smell were determined with stepwise multiple regression analysis, and intergroup differences were assessed with analysis of variance. The reference interval of olfactory thresholds by age was estimated with regression analysis. Nasal resistance was measured by active anterior rhinomanometry. Age and rhinitis were the only variables with significant effect on the olfactory threshold in the whole series. Both the proportion of hyposmic persons and the degree of the impairment of the sense of smell were significantly higher in the rhinitis group than in the control group. The nonallergic patients' sense of smell was poorer than that of seasonal or perennial allergic rhinitis patients. A history of operations for nasal polyposis was associated with hyposmia, but operations for chronic maxillary sinusitis were not. Neither smoking habits nor sex were related to olfactory thresholds. In conclusion, hyposmia in rhinitis patients is partly attributable to age-related changes, but our results indicate that the disease itself impairs the sense of smell.

Odor identification ability and self-reported upper respiratory symptoms in workers at the post-9/11 World Trade Center site

“…If this is the case, the effect is likely due to inflammation within the olfactory epithelium, as has been documented by Kern (2000), rather than by blockage of airflow to the olfactory epithelium. Numerous studies have noted a direct correlation between histopathological changes in the olfactory mucosa and measures of olfactory function in patients with chronic rhinosinusitis (Downey et al 1996;Moll et al 1998;Apter et al 1992;Simola and Malmberg 1998;Doty and Mishra 2001). Strong relationships are not found between airway patency and olfactory dysfunction except in cases of severe blockage, as from extreme polyposis (Doty and Mishra 2001).…”

Cytology of nasal mucosa, olfactometry and rhinomanometry in patients after CO2 laser mucotomy in inferior turbinate hypertrophy.

“…Chronic rhinitis may impair the smell [16]. In patients with inferior turbinate hypertrophy the olfactory alteration seems to be caused by blockage of airflow to the olfactory receptors.…”

The Loss of Smell in Persistent Allergic Rhinitis Is Improved by Levocetirizine due to Reduction of Nasal Inflammation but Not Nasal Congestion (the CIRANO Study)

“…Few studies have previously reported smell disorders in patients with SAR [3,4,5,6,7,8,9] and PAR [8,9] linked to inflammation and not to nasal obstruction. Using ARIA criteria, we demonstrated in a previous study that PER induces a moderate loss of smell [14].…”

“…Although several studies have reported smell disorders associated with SAR [3,4,5,6,7,8,9], few studies have addressed the potential loss of smell in patients with PAR [8,9]. It is well known that the association between AR and chronic rhinosinusitis seriously harms the sense of smell [10,11].…”