Differences between allergic and nonallergic rhinitis in a large sample of adolescents and adults.

BACKGROUND

The aim of this study was to describe differences between allergic rhinitis (AR) and nonallergic rhinitis (NAR) in a large community-based sample of Danish adolescents and adults.

METHODS

A total of 1,186 subjects, 14-44 years of age, who in a screening questionnaire had reported a history of airway symptoms suggestive of asthma and/or allergy, or who were taking any medication for these conditions were clinically examined. All participants were interviewed about respiratory symptoms and furthermore skin test reactivity, lung function and airway responsiveness were measured using standard techniques.

RESULTS

A total of 77% of the subjects with rhinitis had AR, whereas 23% had NAR. Subjects with NAR were more likely to be females, OR = 2.05 (1.31-3.20), P = 0.002, to have persistent symptoms within the last 4 weeks, OR = 1.88 (1.23-2.89), P = 0.003, and to have recurring headaches, OR = 1.94, (1.12-3.37), P = 0.019. On the other hand, subjects with NAR were less likely to have airway hyperresponsiveness, OR = 0.40, (0.24-0.66), P < 0.001, food allergy, OR = 0.40, (0.19-0.36), P = 0.009 and to have been treated with antihistamines in the last 4 weeks, OR = 0.22, (0.13-0.38), P < 0.001 compared with subjects with AR. Subjects with AR were symptomatically worse within their season in terms of sneezing (P < 0.001) and itchy eyes (P < 0.001), compared to subjects with NAR, whereas nasal congestion and rhinorrhea were equally frequent in the two groups (P = 0.901 and P = 0.278, respectively).

CONCLUSIONS

The proportion of subjects with NAR in an adolescent and adult population with rhinitis is around one-fourth. Women have NAR twice as often as men. In general, subjects with NAR have more persistent but equally severe symptoms compared to subjects with AR. However, subjects with AR have more sneezing and itchy eyes within their particular season of allergy compared to subjects with NAR.