Authors' objectives:

This report synthesizes the available evidence on the diagnosis of allergic and nonallergic rhinitis, the question of whether differentiating allergic from nonallergic rhinitis is important, the efficacy of treatments in nonallergic and allergic rhinitis, and how treatment of allergic rhinitis impacts the development of asthma or acute rhinosinusitis.

Authors' results and conclusions: No prospective study explicitly attempted to differentiate allergic from nonallergic rhinitis. The minimum level of testing necessary to confirm or exclude a diagnosis of allergic rhinitis has not been established in the literature. Pharmaceutical companies supported the majority of the treatment trials. Thirteen randomized controlled trials assessed the efficacy of medications for treatment of nonallergic 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. Overall, these treatment modalities were well tolerated and devoid of major side effects. There were 73 randomized controlled trials on the treatment of allergic rhinitis. The majority of studies show a clear benefit on the use of intranasal corticosteroids over either sedating or nonsedating antihistamines for relief of symptoms of nasal allergy. With respect to symptom alleviation in seasonal and perennial allergic rhinitis, study results indicate no consistent differences between sedating and nonsedating antihistamines, though the side-effect profile favors nonsedating antihistamines. No randomized controlled trials were identified that compared immunotherapy with antihistamines or with nasal corticosteroids in the treatment of seasonal and/or perennial allergic rhinitis. Studies provide strong support for the beneficial effect of cromoglycate in the management of both seasonal and perennial allergic rhinitis. A majority of studies reported no serious adverse events associated with the use of antihistamines, cromolyn, or intranasal corticosteroids. Two prospective cohort studies demonstrate an increased likelihood of developing asthma over time in patients with allergic rhinitis, though no study was identified which addressed the question of whether treatment of allergic rhinitis can actually prevent the development of asthma. In addition, though the link between allergic rhinitis and rhinosinusitis is known, we identified no prospective studies on the outcomes of treated and untreated allergic rhinitis.

Authors' recommendations: Beyond skin testing and diagnosis by exclusion, there is no literature on differentiating allergic from nonallergic rhinitis. The data concerning treatment of nonallergic rhinitis is scant and no single agent is identified as being uniformly effective in controlling all the symptoms associated with this condition. In allergic rhinitis treatment, nasal corticosteroids are superior to antihistamines and there is no consistent difference between sedating antihistamines and nonsedating antihistamines for the relief of nasal symptoms. The majority of studies reported no major adverse events associated with current treatments. There is insufficient evidence to address the relationship between allergic rhinitis and the development of asthma or rhinosinusitis.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/tp/rhintp.htm

Year Published: 2002

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)