hypersensitivity reaction

/ˌˈhaɪpərˈsɛnsəˌtɪvədi riˌækʃən/

Definitions of hypersensitivity reaction

1. 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
   types:

   hives, nettle rash, urticaria, urtication

   an itchy skin eruption characterized by weals with pale interiors and well-defined red margins; usually the result of an allergic response to insect bites or food or drugs

   allergic reaction, allergy

   hypersensitivity reaction to a particular allergen; symptoms can vary greatly in intensity

   anaphylaxis

   hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with a substance

   allergic rhinitis

   rhinitis caused by an allergic reaction

   anaphylactic shock

   a severe and rapid and sometimes fatal hypersensitivity reaction to a substance (especially a vaccine or penicillin or shellfish or insect venom) to which the organism has become sensitized by previous exposure

   food allergy

   allergic reaction to a substance ingested in food

   atopic allergy, atopy, immediate allergy, type I allergic reaction

   an allergic reaction that becomes apparent in a sensitized person only minutes after contact

   serum disease, serum sickness

   a delayed allergic reaction to the injection of an antiserum caused by an antibody reaction to an antigen in the donor serum

   delayed allergy, type IV allergic reaction

   an allergic reaction that becomes apparent only hours after contact

   hay fever, pollinosis

   a seasonal rhinitis resulting from an allergic reaction to pollen

   type of:

   hypersensitivity

   pathological sensitivity