any immune response against a foreign antigen that is exaggerated beyond the norm

immune system attacks body's own tissues

disease that result from failure of the immune system

localized or systemic release of inflammatory chemicals in response to antigen, immediate, develops in seconds

antigen that stimulates Type I immediate hypersensitivity reaction

type I immediate hypersensitivity

Allergies:

Th2 release IL-4, stimulates B cells plasma (cells that produce IgE instead of IgG) sensitives to subsequent exposure

Allergies:

when allergen enters the body, binds IgE - triggers release of inflammatory chemicals from granules - generate symptoms

children exposed to environmental antigens like dust mites, molds, parasitic worms, and pet hair are less likely to develop allergies - some research supports this and some contradicts this

allergen binds IgE or surface of sensitized cells and triggers cascade of reactions releasing chemical from granules in cells