What is allergy?

Allergies are an abnormal reaction by the body, which responds in an exaggerated way upon entering into contact with substances from the exterior, to which most other individuals do not normally react. These substances are called allergens.

An allergic reaction is therefore an exaggerated defensive response or hypersensitivity of the immune system, occurring in genetically predisposed individuals, who we call atopic or allergic.

It is unclear why affected individuals are allergic to one substance versus another (allergens), such as pollen, mites, foods, dander, medicines or industrial products.