allergen /al″ərjin/ [Gk, allos, other, ergein, to work, genein, to produce] , an environmental substance that can produce a hypersensitive reaction in the body but may not be intrinsically harmful. Common allergens include pollen, animal dander, house dust, feathers, and various foods. Studies indicate that one of six Americans is hypersensitive to one or more allergens. Methods of identifying specific allergens affecting individuals include the patch test, the scratch test, the radioallergosorbent test, and the Prausnitz-Küstner test. See also allergic reaction, allergy. −allergenic, adj.
