Allergy definitions
acute sinusitis. An infection of limited duration in the sinus cavities. Inflammation that occurs with allergies may block sinus drainage and increase susceptibility to sinusitis. See also chronic sinusitis.
Sinuses are the air-filled, hollow spaces within the bones around your nose….A small area of swelling with surrounding redness is typical of a positive allergy skin test. ...In asthma, airways in your lungs are inflamed and swollen. The muscles surrounding your airways tighten and constrict spontaneously. Membranes in airway linings secrete excess mucus.
Allergy Relief |
Some of the medications used to treat respiratory allergy symptoms include antihistamines, decongestants, nasal sprays and eyedrops. What do medications do? |
adrenaline. See epinephrine.
allergen. Any substance that triggers an allergic reaction. Examples of allergens include pollen, dust mites, animal dander, molds, latex, insect venom and certain foods. See also antibodies, antigen.
allergic reaction. A reaction to a substance (allergen) such as pollen, mold, dust mites, pet dander, food or medication, in a sensitized person. When an allergen enters the body, the immune system releases chemicals such as histamine. These chemicals are responsible for the sneezing, runny nose, itchy eyes, hives, swelling, shortness of breath, wheezing and other signs and symptoms of allergies.
allergic rhinitis. A condition that causes signs and symptoms such as sneezing and runny nose. It occurs after exposure to one or more specific airborne allergy-causing substances (allergens), such as pollen, mold, dust mites and pet dander. Often called hay fever. See also allergic reaction.
allergy shots. Immunotherapy injections that contain small amounts of allergens given on a schedule over a period of time, with the goal of decreasing the body’s sensitivity to that allergen. Also called desensitization shots or hyposensitization shots. See also allergen, immunotherapy.
allergy skin test. A method of determining what allergens a person may be allergic to. For the prick method of skin testing, a small amount of a suspected allergen(s) is placed on the skin of the forearm or back. The area is then pricked or scratched to introduce the allergen beneath the skin surface. A raised bump or reaction indicates a positive skin test and a possible allergy to that substance.
anaphylaxis. A severe and potentially life-threatening allergic reaction to such allergy-causing substances as insect venoms, latex, foods and medications. Signs and symptoms include shock, difficulty breathing, itching and hives, convulsions, and coma.
angioedema. Swelling of the mucous membranes or tissues beneath the skin or of an internal organ, sometimes caused by an allergic reaction.
antibodies. Protein products from the immune system that attack foreign substances (antigens), such as viruses and bacteria, in your body. If you have allergies, your immune system produces allergy-causing antibodies to substances that generally cause no harm, such as pollen, dust mites and pet dander. See also antigen.
antigen. A substance that is foreign to the body and causes antibodies to form. See also allergen, antibodies, histamine.
antihistamines. A group of medications used to treat allergic symptoms by blocking the action of histamine. Histamine is responsible for the sneezing, runny nose, itchy eyes, and other signs and symptoms of allergies. See also histamine.
asthma. A condition characterized by inflammation and congestion in the bronchial tubes, causing wheezing, coughing and difficulty breathing. These signs and symptoms can occur as a result of allergies.
basophil. A type of circulating white blood cell. When an allergen enters the body, basophils react by releasing chemicals such as histamine. These chemicals are responsible for the sneezing, runny nose, itchy eyes, and other signs and symptoms of allergies. See also allergen, histamine.
chronic sinusitis. A prolonged infection or inflammation of the sinus cavities. Inflammation that occurs with allergies may block sinus drainage and increase susceptibility to sinusitis. See also acute sinusitis.
congestion. See nasal congestion.
contact dermatitis. An inflammation of the skin - often characterized by itching and redness - caused by direct contact with an allergy-causing substance.
corticosteroids. Medications resembling cortisone, a hormone the body produces on its own. Taken by inhalation through the nose or into the lungs, intravenously or in pill form (orally), these drugs can help control the symptoms of allergies and asthma by reducing inflammation.
cough. A sharp, forced discharge of air from the lungs, which may occur as a result of allergies.
dander. See pet allergy.
decongestants. A group of medications that help reduce congestion in your membranes by causing the blood vessels that supply those membranes to contract.
desensitization shots. See allergy shots.
dust mite allergy. An allergy to the decayed bodies and fecal material of dust mites - microscopic organisms that thrive in warm, relatively humid conditions. This material is a common element of household dust. See also allergic reaction, allergic rhinitis.
epinephrine. The drug most commonly used to treat anaphylaxis. The drug is derived from a naturally occurring hormone that increases heart rate and blood pressure. Also called adrenaline. See also anaphylaxis.
food allergy. An allergy to certain foods, such as eggs, fish, peanuts and milk. Signs and symptoms include hives, itching, swelling, abdominal pain, diarrhea, nausea and in some cases anaphylaxis. See also allergic reaction, anaphylaxis, food intolerance.
food intolerance. A condition that mimics food allergy, but doesn’t involve the immune system and the release of histamine. See also food allergy.
hay fever. See allergic rhinitis.
high-efficiency particulate air (HEPA) filter. A filter that can help remove from the air allergy- and asthma-causing particles, such as dust, tobacco smoke, pollen and fungal spores.
histamine. A body chemical that is released when the immune system attacks a perceived invader (allergen). Causes signs and symptoms such as hives, swelling, mucus secretion, wheezing, coughing and itchy, runny nose.
hives. An eruption of itchy, red and white raised bumps as a result of histamine released within the skin. Also called urticaria.
hyposensitization shots. See allergy shots.
immunoglobulin E (IgE) antibodies. Of the different types of antibodies produced by the body, IgE antibodies, located on the surface of basophils or mast cells, are most often involved in allergic responses and the subsequent release of histamine. The release of histamine leads to sneezing, watery eyes, itchy nose, and other signs and symptoms of allergies. See also antibodies, basophil, histamine, mast cell.
Immunotherapy. Treatment that aims to desensitize a person to an allergy-causing substance over time. See also allergy shots.
in vitro test for IgE antibody. A blood test that helps determine a person’s specific allergies by assessing the amount of allergy-type antibodies in the bloodstream. Previously called a radioallergosorbent test (RAST). See also allergy skin test.
latex allergy. An allergy to the rubber-tree-produced material used to make many products, such as balloons, rubber bands, condoms and rubber gloves, which can cause contact dermatitis and anaphylaxis.
mast cell. A type of cell that lines the respiratory and gastrointestinal tracts and the skin. When an allergen enters the body, mast cells react by releasing chemicals such as histamine. These chemicals are responsible for the sneezing, runny nose, itchy eyes, and other signs and symptoms of allergies. See also allergen, histamine.
mold allergy. An allergy to the spores of common molds that are carried by the air. See also allergic reaction, allergic rhinitis.
nasal congestion. Swelling of the lining of the nose, often with excess mucus.
nickel allergy. An allergy to the nickel found in items such as jewelry and nickel-plated utensils.
pet allergy. An allergy to the dander shed from the skin, fur and feathers of animals and birds, as well as to the pet’s saliva and urine. See also allergic reaction, allergic rhinitis.
pollen allergy. An allergy to pollen, the fertilizing element of flowering plants. See also allergic reaction, allergic rhinitis.
runny nose. A discharge of mucus-like material from the nose, which may occur as a result of allergies.Also called rhinorrhea.
sneeze. A sudden, forceful, spastic release of air through the nose and mouth, which may occur as a result of allergies.
urticaria. See hives.
wheeze. A high-pitched noise usually heard on breathing out (exhaling), which may occur as a result of narrowed or congested airways caused by asthma. See also asthma.
Revision date: July 3, 2011
Last revised: by Andrew G. Epstein, M.D.