Hypersensitivity Reaction — definition

1. hypersensitivity reaction (Noun)

hypersensitivity reaction (Noun) — An inappropriate and excessive reaction to an allergen (as pollen or dust or animal hair or certain foods); severity ranges from mild allergy to severe systemic reactions leading to anaphylactic shock.

hypersensitivity allergic reaction allergic rhinitis allergy anaphylaxis hives nettle rash urticaria urtication