Allergy Glossary

Allergen: An allergy-causing substance, such as pollen.

Allergic Asthma: An inflammatory disorder of the airways triggered by an allergic reaction to inhaled allergens, characterized by breathing difficulties, coughing, wheezing, and tightness in the chest.

Allergic Rhinitis: (also called hay fever) A seasonally occurring allergy in which contact with pollen releases histamine from nasal tissues, irritating the mucous membrane of the nose and resulting in sneezing, congestion, and itchy eyes.

Allergies: Diseases that occur when the immune system has an exaggerated reaction to substances or situations, evidenced by sneezing, rashes, itching, or difficulty breathing, that would not happen in people without allergies.

Allergist: A doctor who specializes in the diagnosis, treatment, and management of conditions related to allergies.

Anaphylaxis: Severe, immediate, and potentially life-threatening allergic reaction caused by contact with a substance to which the victim has previously been exposed, such as a bee sting.

Animal Dander: Miniscule scales from the fur, feathers, or skin shed by animals that may cause allergic reactions.

Antibiotics: Medications, such as penicillin, used to treat bacterial infections.

Antibody: An immune system protein that perceives and reacts to foreign substances in the body.

Antihistamines: Medications that control the symptoms of allergic reactions by blocking the effects of histamines in the body.

Atopic Dermatitis: An inflammatory skin condition, or rash, that often affects young children. Also known as eczema.

Basophile: A cell in the immune system that links to antibodies and circulates though the blood.

Beta Blockers: Blood pressure medications that widen the blood vessels, thus easing the pumping action of the heart. Beta blockers, which counteract the effects of epinephrine, should not be used on patients being treated for anaphylactic shock.

Bronchial Tubes: Either of the two primary tubes that lead into the left and right portions of the lungs.

Challenge Test: A test in which small amounts of suspected allergens are administered to patients in increasing amounts in an attempt to confirm an allergy.

Conjunctivitis: Known as pinkeye, conjunctivitis is an inflammation of the mucous membrane, or conjunctiva, surrounding the eye.

Contact Dermatitis: A skin rash or hives resulting from contact with an allergen.

Corticosteroid: A medication with anti-inflammatory action prescribed for the treatment of allergy-related itching and swelling.

Cromolyn Sodium: A medication with anti-inflammatory action prescribed for the treatment and prevention of allergic rhinitis.

Decongestants: Prescription and over-the-counter medications used to relieve congestion of the mucous membranes of the nose or eyes.

Drug Allergies: Allergic reactions prompted by an exaggerated immune response to penicillin, aspirin, and other medications.

Dust Mites: Microscopic acarid arachnids found in house dust.

Eczema: An inflammatory skin condition, or rash, that often affects young children, also known as atomic dermatitis.

Eosinophil: A granulocyte, or immune cell, that is present at sites of allergic reactions and can lead to tissue damage.

Epinephrine: Also known as adrenaline, epinephrine is a medication administered in the event of anaphylaxis in an attempt to raise blood pressure and bring the heart rate back to normal.

EpiPen: A needle that contains a pre-measured dose of epinephrine for self-injection during an anaphylaxis episode.

Eye Allergies: Also known as allergic conjunctivitis, eye allergies are exaggerated immune system responses to allergens that get into the eye.

Food Allergies: Exaggerated immune system responses to food-related allergens.

Heparin: An anti-coagulant found in mast cells and basophiles that are believed to contribute to the severity of allergic reactions.

Histamine: A chemical found in mast cells and basophiles that contributes to the severity of allergic reactions.

Hives: Itchy, raised bumps on the skin triggered by an allergic reaction to food, medication, or other allergens. See Urticaria.

Immunoglobulin E (lgE): A class of antibody found in type 1 hypersensitivity which plays a role in allergic diseases and conditions.

Immunotherapy: A series of shots in which patients are given increasingly higher doses of their allergen in an attempt to lessen their sensitivity to allergy triggers such as hay fever, animal allergies, and insect stings.

Indoor Allergies: Exaggerated immune system responses to allergens found indoors, including pet dander, mold spores, dust mites, and others.

Insect Allergies: Exaggerated immune system responses to specific insect proteins released by insect bites or stings.

Insulin: A protein hormone that regulates blood sugar levels sometimes taken by people with diabetes.  Insulin derived from animals has been known to cause allergic reactions.

Intradermal Test: An allergy diagnosis test in which an allergen is injected right under the skin.

Late Phase: A period ranging from four to twenty-four hours during which tissue damage may occur following exposure to an allergen.

Latex Allergies: Exaggerated immune system responses to proteins found in natural rubber or latex. Symptoms include hand dermatitis, hives, eczema, and respiratory problems.

Leukotriene Modifiers: Medications used to block the action of leukotrienes in the body that can trigger asthma and allergy symptoms.

Lymphocyte: A type of immune cell sometimes responsible for the tissue damage that can occur in the late phase of allergic reactions.

Mast Cell: An immune system cell found in the connective tissues of the skin, bronchial tubes, nose, and gastrointestinal tract, which contains substances that can trigger allergic responses.

Neocromil Sodium: A medication administered by inhaler used to treat asthma-related inflammation.

Neutrophil: A type of immune cell sometimes responsible for the tissue damage that can occur in the late phase of allergic reactions.

Otitis Media: An inflammatory infection of the middle ear. 

Outdoor Allergies: An exaggerated immune response to allergens found in the outdoors, including pollen, mold, and insect bites.  Also known as hay fever.

Radioallergosorbant Test (RAST): A test administered to determine how many antibodies the blood produces when mixed with a suspected allergen.

Rhinitis: An inflammation of the mucous membranes of the nose, characterized by sneezing, itching, congestion, and discharge.

Sinusitis: An inflammation of one or more of the sinuses, characterized by pain, tenderness, and other flu-like symptoms.

Skin Allergies: An exaggerated reaction of the immune system to allergens that come in contact with the skin, manifested in rashes, hives, and eczema.

Skin Prick Test: A test in which a small amount of an allergen is place on the skin which is then scratched with a needle to see if a reaction occurs.

Urticaria: An allergic reaction to food, medication, or other allergens, which manifests itself in hives, itchy raised bumps on the skin that are often white in the middle and red around the edges.

Urushiol: A toxic oil found in all parts of poison ivy, oak, and sumac plants that causes itchy rashes.