Allergic rhinitis is a chronic inflammatory disease of the upper airways characterized by one or more of the following symptoms: nasal congestion, rhinorrhea, sneezing, and itching. Allergic rhinitis can lead to sleep disturbances, missed work and school, and adversely affect quality of life.
Allergic nasal reactions are mediated by immunoglobulin E (IgE). Airborne allergens react with antigen-specific IgE bound to mast cells, triggering a release of inflammatory mediators such as histamine and leukotrienes. Both early- (immediate) and late-phase allergic reactions occur following allergen exposure. Early-phase reactions happen within seconds to minutes and are due to the release of histamine, leukotrienes, tryptase, and cytokines. Sneezing, itching, rhinorrhea, and congestion are typical symptoms. The release of cytokines results in the infiltration of inflammatory cells such as basophils and eosinophils. This produces a late-phase reaction occurring 4 to 8 hours after allergen exposure. With continued exposure to the allergen, the late-phase inflammatory response results in chronic symptoms of allergic rhinitis.
Patients with allergic rhinitis may present with the following symptoms: clear rhinorrhea, nasal congestion, allergic conjunctivitis, sneezing, postnasal drip, and itchiness in the nose, ears, and/or eyes. Allergic shiners (swelling and darkening of circles under the eyes due to nasal obstruction and venous congestion) and allergic salute (upward rubbing of the nose) are less common signs.
Allergic rhinitis is differentiated from other types of rhinitis by a thorough medical history, complete medication history, and physical examination. Collecting information on symptoms, patterns, and allergic triggers can provide a presumptive diagnosis. Allergy skin testing or blood tests to identify allergen-specific IgE antibodies may be used to confirm the diagnosis of allergic rhinitis.
Depending on the frequency and severity of symptoms, allergic rhinitis is classified as mild intermittent, mild persistent, moderate-severe intermittent, or moderate-severe persistent. Patients who experience symptoms less than 4 days per week or for less than 4 consecutive weeks meet the criteria for intermittent allergic rhinitis. The persistent classification applies to patients with symptoms that occur more than 4 days per week and for more than 4 consecutive weeks. If symptoms do not impact daily activities, sleep patterns, work, or school, then the disease is considered mild. If these activities are impacted by allergic rhinitis, then the patient has a moderate-severe form. Other descriptors for allergic rhinitis include seasonal, perennial, or episodic. In seasonal allergic rhinitis, symptoms occur primarily during the spring and fall (high pollen seasons). Patients with perennial allergic rhinitis have symptoms throughout the year. Patients with episodic allergic rhinitis experience symptoms with sporadic exposures to aeroallergens.
Patients should be advised to avoid offending allergens (pollen, fungi, mold, dust mites, and animals) if possible. During high pollen seasons, patients should limit outdoor exposure. Patients may take the following additional precautions to minimize exposure to indoor allergens: use a high-efficiency particulate air (HEPA) filter, vacuum with a ...