Allergens are substances that cause allergic disease in people. Antigens, or protein particles like pollen, food, or animal dander enter our bodies through a variety of ways. If the antigen causes an allergic reaction, that particle is considered an allergen. These allergens can get into our body by:
Inhalation
Examples are airborne pollens of trees, grasses and weeds; house dust that contains dust mite waste, mold spores, pet dander and latex dust.
Ingestion
Frequent culprits include shrimp, peanuts, and other nuts.
Injection
Such as medications delivered by needle and venom from insect stings or bites.
Absorption Through the Skin
Plants such as poison ivy, sumac and oak, as well as latex are examples.
Heredity
You may inherit the genetic capability to become allergic, but that does not mean you are automatically allergic to specific allergens. Several factors must be present for allergic sensitivity to be developed, including the specific genes acquired from your parents and the degree and length of exposure to allergens.
Contact Dermatitis Caused by Allergens
This is a type of allergy in which heredity does not play a role. Exposure to poison ivy, for instance, may not cause a rash the first time, but a reaction may appear after subsequent exposure and can be quite severe. This may also be true of substances such as dyes, metals and chemicals in deodorants and cosmetics.