Allergen

allergen /al·ler·gen/ (al´er-jen) an antigenic substance capable of producing immediate hypersensitivity (allergy).allergen´ic

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pollen allergen  any protein antigen of weed, tree, or grass pollens capable of causing allergic asthma or rhinitis; pollen antigen extracts are used in skin testing for pollen sensitivity and in immunotherapy (desensitization) for pollen allergy.

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al·ler·gen (lr-jn)

n.

1. A substance, such as pollen, that causes an allergy.

2. See antigen.

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aller·genic (-jnk) adj.

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Allergen

A foreign substance, such as mites in house dust or animal dander which, when inhaled, causes the airways to narrow and produces symptoms of asthma.

Mentioned in: Allergic Rhinitis, Allergies, Allergy Tests, Anosmia, Asthma, Delayed Hypersensitivity Skin Test, Detoxification, Deviated Septum, Eyelid Disorders, Hepatitis, Autoimmune, Hives, Hypersensitivity Pneumonitis, Lung Diseases Due to Gas or Chemical Exposure, Nasal Polyps

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allergen,

n allergy-producing foreign substance.

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allergen (al´urjen),

n a substance capable of producing an allergic response or antigen. Common allergens are pollens, dust, drugs, and foods. See also antigen.

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allergen

1. a substance, protein or nonprotein, capable of inducing allergy or specific hypersensitivity.

2. an extract of any substance known to cause allergy.

Allergens are used to test a patient for hypersensitivity to specific substances (see skin test). They are also used to densensitize or hyposensitize allergic individuals. See immunotherapy.

Almost any substance in the environment can be an allergen. The list of known allergens includes plant pollens, spores of mold, food preservatives, dyes, drugs, inorganic chemicals and vaccines. Allergens can enter the body by being inhaled, swallowed, touched or injected. Following primary exposure to an allergen, subsequent exposures result in hypersensitivity (allergic) reactions which may be immediate or delayed, local or systemic and include anaphylaxis and contact dermatitis.

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alum-precipated allergen

an allergen extract used in intradermal and scratch allergy skin testing; the allergen is adsorbed onto alum to slow antigen release and provide a slower, more persistent immune stimulation. Local tissue reactions and skin nodules may follow their use.

aqueous allergen

a form of allergen extract used in intradermal and scratch allergy skin testing. In hyposensitization regimes, it is rapidly absorbed, but requires more frequent administration.

emulsion allergen

allergen extracts prepared in propylene glycol glycerin, or mineral oil. They give the most sustained effect when used in hyposensitization regimes.

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allergen Immunology A substance–eg, pollen, dander, mold, which can evoke an immediate-type hypersensitivity–allergic reaction, triggering a release of histamine. See Airborne allergen, Cockroach allergen, Feline allergen, Immunogenic allergen.