Olfactory function in chronic rhinitis subtypes: Any differences?

Introduction: Olfactory dysfunction is a common problem in rhinological disease, but it has been few evaluated among patients with different chronic rhinitis subtypes. The aim of this study was to assess olfactory function in patients with allergic rhinitis (AR), non-allergic rhinitis (NAR) and mixed rhinitis (MR). Materials and methods: A total of 122 patients with AR, NAR, and MR were included in the study. Sniffin’ Sticks test was applied to all groups. The study groups were compared in terms of odor scores and an association between olfactory dysfunction and rhinitis grading, according to ARIA (Allergic Rhinitis and its Impact on Asthma) criteria, was also investigated. Results: A significant difference was observed between NAR patients and the two other study groups with respect to all odor scores. TDI (Threshold, Discrimination, Identification) score, for overall olfactory function, resulted significantly lower in NAR patients than that in the other two groups (P=0.038). Conversely, no significant difference was observed between patients with AR and MR. Consistent with ARIA classification, NAR patients suffered mostly from persistent symptoms, whereas, AR patients generally suffered by intermittent symptoms, as well as MR patients, but this last with a significative higher presence of patients with persistent symptoms, when compared to AR group (P<0.05). A significative association was also observed between lower TDI scores and presence of persistent rhinitis symptomatology (P<0.001). Conclusions: Impaired olfaction is a feature more evident in NAR patients when compared to the other rhinitis subtype and it was much more affected by longer duration of rhinitis symptomatology rather than severity.