Overview of comorbid associations of allergic rhinitis.
Allergic rhinitis affects approximately 20% of the U.S. population. An association between allergic rhinitis and conditions including asthma, sinusitis, otitis media, nasal polyposis, respiratory infections, and even orthodontic malocclusions has been observed. Clinical research has identified shared pathogenic mechanisms, epidemiologic correlations, and findings from allergy testing to indicate that these conditions represent long-term physical consequences in allergic individuals. The positive response of patients afflicted with these conditions to antiallergic treatment further enhances the association between allergic rhinitis and other airway diseases. The use of nasal corticosteroids in patients with rhinitis and asthma reduces not only rhinitis symptoms but also asthma symptoms and airway reactivity to methacholine challenge. Similarly, antihistamines, with or without decongestants, result in improvement of objective measurements of pulmonary function. In the treatment of acute sinusitis, the combination of an intranasal corticosteroid and an antibiotic provides greater benefit than an antibiotic alone. Treatment strategies for allergic rhinitis should be directed at controlling the symptoms of allergic rhinitis and reducing the development of physical complications in susceptible persons. Three techniques for the treatment of allergic rhinitis are used, including avoidance of offending allergens, selection of appropriate pharmaceuticals, and allergy immunotherapy. Appropriate treatment may spare some patients of related airway diseases and may also reduce the overall cost of care. The broadened scope of allergic rhinitis and increased prevalence of IgE-mediated diseases have heightened awareness regarding the profound consequences of allergic rhinitis and the importance of effective treatment.