allergic reaction, defined as sensitivity beyond what is considered normal
The first time an antigen (allergen) is encountered, the body becomes "sensitized" or forms antibodies, but no visible signs of hypersensitivity is exhibited.
1.) the allergen is encountered by mast cells and basophils, each coated with a particular group of antibodies that wsere formed during the first encounter 2.) then, chemicals such as histamine are released 3.) The severity of the reaction depends upon where in/on the body the chemicals are released
Tendency of allergies being inherited
at least one in five people have had or will have allergies related to hay fever (most common allergy)