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Allergy glossary


A substance that triggers an allergic reaction.

Allergic Rhinitis

An allergy affecting the mucus membrane of the nose. Seasonal allergic rhinitis is often called "hay fever."


A doctor that diagnoses, treats, and manages allergy-related conditions.


A life-threatening allergic reaction that involves the entire body. Anaphylaxis may result in shock or death, and thus requires immediate medical attention

Animal dander

The small scales or pieces of skin, often containing proteins secreted by oil glands, which are shed by an animal. These proteins are the major causes of allergies to pets.


A class of medications used to treat bacterial infections. Certain antibiotics, such as penicillin, may cause an allergic reaction in some people.


A protein in the immune system that recognizes and attacks foreign substances in the body.


A medication used to prevent or treat seizures. Certain anticonvulsants may cause an allergic reaction in some people.


A class of medications used to block the action of histamines in the body and prevent the symptoms of an allergic reaction.


An inflammatory disorder of the airways, causing periodic attacks of wheezing, coughing, chest tightness, and shortness of breath.

Atopic dermatitis

A chronic skin rash, also known as "eczema," that often appears in the first few years of life.


An immune system cell that attaches to antibodies and circulates throughout the blood.

Beta blockers

A class of blood pressure medications that ease the heart's pumping action and widen the blood vessels. Beta-blockers counteract the effects of epinephrine used for emergency treatment of anaphylactic shock and should not be used during immunotherapy.

Bronchial tubes

The lower sections of the airway that lead into the lungs.

Challenge test

A test used to confirm an allergy to specific substance. A doctor will administer small but increasing amounts of a suspected allergen until an allergic response is noticed. Due to the risk of anaphylaxis, this should only be performed under a controlled setting.


Inflammation of the conjunctiva, or the mucous membrane surrounding the eye. Also known as pinkeye.

Contact dermatitis

An allergic reaction resulting from skin contact to an allergen.


An anti-inflammatory medication used to treat the itching and swelling associated with some allergic reactions.

Cromolym sodium

An anti-inflammatory nasal spray used to treat and sometimes prevent allergic rhinitis.


A class of medications used for nasal congestion. Decongestants are available in oral doses, nasal sprays, or eye drops (for conjunctivitis).

Dust mites

A microscopic organism that lives in dust.


See Atopic dermatitis.


A specific type of immune cell that can cause tissue damage in the late phase of an allergic reaction.


A medication used for immediate treatment of anaphylaxis by raising blood pressure and heart rate back to normal levels. Epinepherine is also known as adrenaline.


A device used to inject epinephrine during an anaphylaxis attack.


A chemical released by basophils and mast cells that causes nearby tissues to become swollen and inflamed.


A chemical released by basophils and mast cells that causes nearby tissues to become swollen and inflamed.


See urticaria.


High blood pressure. When blood pushes against artery walls harder than normal.

Immunoglobulin E

A type of antibody responsible for most allergic reactions.


A series of shots that help build up the immune system's tolerance to an allergen.


A hormone that regulates blood sugar levels. Diabetics who take insulin derived from animals may have allergic reactions.

Intradermal test

A test where an allergen is injected just inside the skin. Intradermal tests are generally used when results from a skin prick test are unclear.

Late Phase

The period 4 - 24 hours after exposure to an allergen where tissue damage may occur.


Inflammatory substances that are released by mast cells during an allergic response or asthma attack.


A specific type of immune cell that can cause tissue damage in the late phase of an allergic reaction.

Mast cell

An immune system cell which attaches to antibodies and is located in the tissue that lines the nose, bronchial tubes, gastrointestinal tract, and the skin

Neocromil sodium

An inhaled medication used to treat inflammation involved with asthma.

Otitis media

A middle ear infection. Otitis media with effusion occurs when fluid builds up within the ear.

Radioallergosorbant Test (RAST)

A blood test that measures the amount of IgE antibody to a specific allergen.


An inflammation of the nasal passageways, particularly with discharge.


An inflammation or infection of one or more sinuses. The sinuses are hollow air spaces located around the nose and eyes.

Skin prick test

A test where a needle is used to scratch the skin with a small amount of allergen. A response can usually be seen within 15 - 20 minutes.


Raised areas of the skin that are often red, warm, and itchy. Urticaria is also known as hives.


An oil found on poison ivy, oak, and sumac.