Allergy Glossary

Here’s a glossary of terms and definitions frequently encountered in discussions about allergies.

Allergen: A substance the body perceives as harmful.

Allergy: An exaggerated immune system response to an otherwise harmless substance, triggered by the release of histamines in the body.

Allergy Shots: See “Immunotherapy.”

Antibodies: Proteins produced by white blood cells to neutralize the threat of foreign substances.

Antihistamine: Medication that blocks the effects of histamine, a chemical released in the body during an allergic reaction.

Corticosteroid: A group of anti-inflammatory drugs that reduce swelling and relieve other symptoms of allergies.

Decongestant: Medication that shrinks swollen nasal tissue to relieve congestion, runny nose and other allergy symptoms.

Dust mites: Microscopic insects found in household dust. Typically found in mattresses, pillows, carpets and curtains; responsible for allergic reactions in some individuals.

Epinephrine: Also known as adrenaline; a hormone released by the adrenal gland that dilates the airways and increases blood flow. Used to treat anaphylaxis.

Histamine: A chemical substance released by the immune system to neutralize the threat of allergens. Responsible for the majority of allergy symptoms including runny nose, sneezing and itchiness.

Immune System: A group of cells and proteins that serve as the body’s defense system, protecting against foreign substances and infections.

Immunoglobulin: Another name for “antibodies.”

Immunotherapy: Also known as “allergy shots,” this allergy treatment helps the body build up a tolerance to an allergen over time by introducing small amounts of the offending substance. Immunotherapy is a long-term allergy solution that leads to a reduction or elimination of symptoms.

Mast cell: A white blood cell that releases histamine when an allergen triggers the production of antibodies.

Nasal spray: Medication used to prevent or treat nasal allergy symptoms.

Pollen: A powdery substance released by plants and trees. Causes an allergic response in sensitive individuals.

RAST: A blood test used to identify the allergen responsible for causing symptoms.