An evidence report from the Agency for Healthcare Research and Quality (AHRQ) provides a review of the available literature on the various treatments for allergic and nonallergic rhinitis. The complete report, “Evidence Report/Technology Assessment No. 54—Management of Allergic and Nonallergic Rhinitis,” is available at www.ahrq.gov. Printed copies may be obtained free of charge from the AHRQ Publications Clearinghouse (800-358-9295). For this report, the American Academy of Family Physicians served as the science partner, and the American College of Allergy, Asthma and Immunology and the American Academy of Allergy, Asthma and Immunology provided technical experts.
Twenty to 40 million Americans are affected by allergic rhinitis, making it the sixth most prevalent chronic illness. It is responsible for at least $1.8 billion annually for the direct cost of physician visits and medication expenses, and the estimated value of lost productivity to employers and society is nearly $3.8 billion annually. Rhinitis, classified as allergic or nonallergic, is a disorder characterized by inflammation of the mucous membranes lining the nasal passages. Symptoms of allergic rhinitis include sneezing, nasal itch, rhinorrhea, nasal obstruction, post-nasal drip, and sometimes pain. It can be seasonal or perennial, depending on the timing or periodicity of symptoms. Nonallergic rhinitis is characterized by sporadic or persistent perennial nasal symptoms. Symptoms are similar to allergic rhinitis, but with less prominent nasal itch and conjunctival irritation.
Antihistamines vs. Nasal Corticosteroids
The majority of studies favor the use of intranasal corticosteroids over sedating or nonsedating antihistamines for relief of symptoms of nasal allergy. These results are true for seasonal and perennial allergic rhinitis.
Antihistamines vs. Immunotherapy
Direct comparisons between these two therapies with respect to efficacy are not likely to be done. Immunotherapy is generally considered to be a long-term disease-modifying treatment requiring months to years of treatment, and antihistamines are most often used for immediate symptom relief.
Nasal Corticosteroids vs. Immunotherapy
No randomized controlled trials were identified that directly compared immunotherapy with intranasal corticosteroids in treating seasonal or perennial allergic rhinitis.
Sedating vs. Nonsedating Antihistamines
Study results indicate no consistent benefit of sedating antihistamines over nonsedating antihistamines with respect to symptom alleviation in seasonal and perennial allergic rhinitis, but the side-effect profile is more favorable with nonsedating antihistamines.
Cromoglycate is beneficial in the management of seasonal and perennial allergic rhinitis. De-congestant drugs relieve nasal congestion but not other symptoms. Ipratropium reduces rhinorrhea and post-nasal drip.
In most trials of antihistamines, no major events were reported. When events were noted, somnolence, dry mouth, dizziness, and headache were reported most frequently and seen almost exclusively with the sedating antihistamines. Epistaxis, headache, and pharyngitis were the most frequently reported side effects of nasal corticosteroids. No major adverse events were reported with the use of cromolyn. Among the minor events were a high frequency of nasal irritation, headache, and nasal congestion.
The U.S. Food and Drug Administration (FDA) has approved a topical nasal product, azelas-tine, for the treatment of vasomotor rhinitis.
Intranasal corticosteroids (budes-onide) are recommended by the FDA for long-term therapy in nonallergic rhinitis.
The only available orally active decongestant, pseudoephedrine, was not identified in any trial concerning management of nonallergic rhinitis.
No studies of leukotriene modifiers were identified. Each study of ipratropium demonstrated its efficacy in reducing nose-blowing frequency and rhinor-rhea. Active treatment using cromoglycate showed improvement in symptoms of rhinitis.
No side effects were reported with use of antihistamines, nasal corticosteroids, or cromoglycate. Drowsiness, nausea, and headache were associated with sympatho-mimetic use. Significant nasal dryness and irritation were reported with ipratropium.
Studies have revealed that a significant proportion of patients have allergic rhinitis symptoms in advance of the development of clinical symptoms of asthma. None of the studies addressed whether treatment of allergic rhinitis can prevent the development of asthma.
Cross-sectional studies have shown an increased prevalence of acute and chronic bacterial sinusitis among patients with allergic rhinitis. To determine the effect of treating allergic rhinitis on the development of sinusitis, data from prospective studies are needed.
Better assessment of allergic and nonallergic rhinitis is required. The minimum amount of testing required to differentiate between these conditions remains uncertain. Other studies needed include the role of antihistamines for symptom relief in nonallergic rhinitis, the role of nasal cor-ticosteroids in nonallergic rhinitis, the role of cromoglycate use in nonallergic rhinitis, and whether interventions for allergic rhinitis have preventive effects on asthma.