Noun
any substance that can cause an allergy
Source: WordNetAllergists do skin tests in one of two ways: either dropping some purified liquid of the allergen onto the skin and pricking the area with a small needle; or injecting a small amount of allergen under the skin. Source: Internet
Allergy shots and allergy drops or tablets that go under the tongue are like vaccines: They expose the immune system to small amounts of the offending allergen. Source: Internet
And if a food allergy is suspected to be the cause, further testing may be required to identify the food allergen. Source: Internet
Contact dermatitis is typically treated by avoiding the allergen or irritant. citation citation Antihistamines may be used to help with sleep and to decrease nighttime scratching. Source: Internet
A patch test is used to identify the causative allergen in the case where conjunctivitis is caused by allergy. Source: Internet
As the male members of the Injustice Gang discover, much to their chagrin, Aresia's true plan is to release an allergen that will eliminate the male population. Source: Internet