ALLERGIC RHINITIS

Abstract

Allergic rhinitis is one of the most common chronic diseases in the United States, affecting quality of life for 15% to 20% of the population. The allergic process is mediated genetically by a predelection for a TH2 lymphocyte response to antigens, which leads to the production of IL-4 and IL-5. These interleukins play a direct role in mediating production of specific IgE (IL-4) and eosinophils (IL-5). Clinical disease occurs as a consequence of allergen interacting with IgE on mast cells and the inflammatory tissue effects of eosinophils. The diagnosis of allergic rhinitis is suspected on the basis of directed history taking and physical examination. Further support for the diagnosis is obtained from nasal cytology that shows significant eosinophilia. Ultimately, a firm diagnosis is based on the demonstration of the presence of specific IgE by skin or RAST tests. Allergic rhinitis is associated commonly with and may play a primary pathophysiologic role in otitis media, sinusitis, and asthma. These secondary disorders occur because of upper airway inflammation and the release of various vasoactive mediators, including histamine, prostaglandins, and leukotrienes. The management of allergic rhinitis includes environmental controls, pharmacotherapy, and, in selected patients, immunotherapy. Environmental measures target perennial indoor triggers (e.g., dust mites, cockroaches, pets, and molds), with emphasis on the bedroom and heating or cooling systems. Primary pharmacotherapy includes antihistamines and nasal corticosteroids, with cromolyn, decongestants, and anticholinergics as adjuncts for control. Immunotherapy is considered for patients with suboptimal clinical response to aggressive environmental control and medications. Given the current understanding of the disease, diagnostic tests, and available therapy, the patient suffering from allergic rhinitis in the new millennium should expect marked symptom relief and improvement in quality of life, with minimal side effects as a consequence of treatment.