Dictionary

allergen A substance that can cause an allergic reaction. Common allergens include ragweed pollen, animal dander, and mold.

allergic conjunctivitis Inflammation of the whites of the eyes (conjunctivae), with itching, redness, and tearing, due to allergy.

allergic granulomatosis See Churg-Strauss syndrome.

allergic reaction A hypersensitive immune response to a substance. An allergic reaction can occur when the immune system attacks a normally harmless substance. The allergic immune system calls upon a protective antibody called immunoglobulin E (IgE) to fight these invading substances. In the melee, cells called mast cells release a variety of strong chemicals, including…

allergic rhinitis Medical term for hay fever, an allergic reaction that mimics a chronic cold. Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing of the eyes. Postnasal dripping of clear mucus frequently causes a cough, loss of smell is common, and occasionally loss of taste. Nosebleeds may occur….

allergic rhinitis, perennial Allergic rhinitis that occurs throughout the year.

allergic rhinitis, seasonal Allergic rhinitis that occurs during a specific season.

allergic salute The characteristic gesture of a person with allergic rhinitis: rubbing his or her nose with the index finger.

allergic vasculitis See Churg-Strauss syndrome.

allergy Hypersensitivity of the body’s immune system in response to exposure to specific substances (antigens), such as pollen, bee stings, poison ivy, drugs, or foods. See also allergic reaction; anaphylactic shock.

allergy desensitization Stimulation of the immune system with gradually increasing doses of the substances to which a person is allergic in order to modify or stop the allergic response. This form of treatment is very effective for allergies to pollen, mites, animal dander, and stinging insects, including bees, hornets, yellow jackets, wasps, velvet ants, fire…

allergy scratch test See allergy skin test.