Glossary of Allergy Terms

Allergic
Relating to the body's response when triggered by an allergen.

Allergen
A small airborne particle that causes the body's allergic and hypersensitive response.

Allergy
The body's altered reaction to allergen exposure, resulting in hypersensitive response.

Allergy medicine or medication / Allergy control or relief products
Nasal sprays or pills that help to reduce allergic reaction.

Antihistamine
Medicine that blocks the effects of histamine, the chemical that causes allergy symptoms.

Black mold
Stachybotrys chartarum, a greenish-black mold that can cause allergy symptoms.

Dust mite allergy
A common allergic reaction to tiny (invisible to the naked eye) insects called dust mites.

Environmental irritant
Smoke, car exhaust, household cleaning products, and perfume. Unlike seasonal allergies, environmental irritants cause symptoms all year round.

Grass allergy
A common allergic reaction caused by exposure to certain types of grass.

Hay fever
A seasonal, often intense allergic reaction to pollen. Hay fever can include symptoms such as sneezing, drippy nose, and itching or watering eyes.

Histamine
A naturally occurring chemical within the body that, in reaction to a trigger, causes allergy symptoms.

Mast cells
The cells in the body that produce the chemical histamine, which causes allergy symptoms.

Mold allergy
A common allergic reaction triggered by exposure to mold.

Nasal spray
A topical treatment that delivers medicine directly to the nasal passages inside the nose.

Outdoor allergies
The body's response to outdoor sources of allergens such as grass, ragweed, and pollen.

Pollen allergy
A common allergic reaction triggered by exposure to pollen, a tiny powder from plants and trees.

Postnasal drip
A common allergy symptom caused by flow of mucus from the nasal cavity to the back of the throat.

Pseudoephedrine
A decongestant that may cause restlessness or difficulties sleeping. Pseudoephedrine should not be used by people with diabetes, enlarged prostate, heart or blood vessel disease, or overactive thyroid.

Rebound congestion
Chronic nasal stuffiness resulting from overuse of nasal congestants containing a topical vasoconstrictor (such as Afrin®).

Respiration
Another word for “breathing”.

Rhinitis
The medical name for hay fever. Seasonal allergic rhinitis refers to symptoms caused by seasonal allergens. Nonallergic vasomotor rhinitis refers to symptoms caused by environmental irritants.

Seasonal allergies
Allergies that cause symptoms only at certain times of the year.