OBJECTIVETo investigate and describe the differences in age, sex, seasonality distribution, and related environmental factors between patients with non-allergic rhinitis (NAR) and allergic rhinitis (AR).

METHODSOne hundred and eleven patients with NAR and 112 patients with AR were enrolled in this study. All patients were first diagnosed in outpatient department between January and August 2010. Questionnaires were distributed to all participants to record the general information, medical history, and the factors relevant to symptom onset. Statistical analysis was performed using a SPSS13.0 software.

RESULTSThe proportion of patients with NAR increased with age, compared to patients with AR. The peak age was 21 - 30 years old in patients with NAR, whereas 11 - 20 years old in patients with AR. In adults more than 18 years old, the average age (years, x(-) ± s) of patients with NAR (38.6 ± 14.5) was significantly higher than those with AR (32.8 ± 13.0; t = 2.58, P = 0.024). NAR was more likely to be males before 30 years old, while after 30 years old, it likely to be female predominance. The same case occurred in AR subjects but in their 20 years old. NAR was symptomatically worse in winter (χ(2) = 27.57, P = 0.000), whereas AR worse in spring (χ(2) = 13.75, P = 0.003). The cases of NAR were significantly more than those of AR during the winter season (χ(2) = 12.34, P = 0.000). Among the disease-related environmental factors, living or working place near the traffic artery had 1.94-fold increased risk for development of NAR compared with AR; however, living or working in ground floor or sunshine time less than 2 h per day had 1.77- or 1.91-fold increased risk for development of NAR compared with NAR. Subjects with personal or family history of allergic disease had 2.14 to 4.06-fold increased risk for development of AR compared with NAR. The self-reported predisposing factors in NAR patients were mainly including temperature shift (56.3%), common cold (52.8%), climate change (32.4%), and strong odors (31.1%). However, there were no significant differences in these nonspecific triggers between NAR and AR (all P > 0.05).

CONCLUSIONThere are significant differences in the distribution of age, sex and seasonality, personal and family history of allergic disease, and some environmental factors relevant to the onset of symptom between patients with NAR and AR.