Non-allergic rhinitis involves chronic sneezing or having a congested running nose. The symptoms of non-allergic rhinitis are similar to symptoms of allergic rhinitis, but there is no identified allergic reaction involved. A total of 10,670 individuals were included in the analysis, corresponding to a response rate of 73%. The results revealed a high prevalence of self-reported non-allergic rhinitis, 19%, almost as high as the prevalence of self-reported allergic rhinoconjunctivitis, 24%. In contrast to current clinical opinion, we did not find a significant increase in the prevalence of non-allergic symptoms with increased age. A reduced sense of smell was twice as common in the non-allergic group, 23%, as in the healthy population. The prevalence of rhinitis symptoms differed according to smoking habits.
Pharmaceutical companies supported the majority of the treatment trials. Thirteen randomized controlled trials assessed the efficacy of medications for treatment of non allergic rhinitis symptoms. Only one study examined the role of antihistamines and three studies examined the efficacy of nasal corticosteroids. Oral decongestants are effective in controlling the symptom of nasal congestion and ipratropium bromide is beneficial in the management of rhinorrhea. There is little published evidence for use of antihistamines or nasal corticosteroids for the management of nonallergic rhinitis.