Definition: An allergen is a substance that can trigger—or set off—an allergic reaction in the body. This reaction can cause symptoms in the nose, eyes, mouth, throat, skin, and airways. In people with allergy-induced asthma, the resulting asthma symptoms are most often wheezing, cough, chest tightness, and shortness of breath.
Pronunciation: AL-lur-JEN
Also Known As: allergy triggers, asthma triggers
Examples: Grass, tree, and weed pollens are examples of allergens. So is pet dander, cockroach sheddings, mold spores, and dust mites.
