Allergic Reaction

∞ generated and posted on 2016.01.10 ∞

Manifestation of an immune system hypersensitivity to a substance, often of foreign (not body) origin.

Allergic reactions are in response to what are known as allergens – to which IgE reacts – and involve an excessive activation of the histamine-producing mast cells and basophils. See also anaphylaxis.