hypersensitivity
Abnormal sensitivity, a condition in which there is an exaggerated response by the body to the stimulus of a foreign agent. See allergy.
- contact h. 1. SYN: contact dermatitis. 2. SYN: delayed reaction.
- delayed h. 1. SYN: cell-mediated immunity. 2. SYN: delayed reaction. 3. a cell-mediated response that occurs in immune individuals peaking at 24–48 hours after challenge with the same antigen used in an initial challenge. The interaction of T-helper I lymphocytes with MHC class II positive antigen-presenting cells initiates the response. This interaction induces the T helper 1 and macrophages at the site to secrete cytokines, which are the major players in the reaction. Called tuberculin-type h..
- immediate h. an exaggerated immune response mediated by antibodies occurring within minutes after exposing a sensitized individual to the approximate antigen; also called Type I h.. Clinical symptoms include atopic allergy and systemic anaphylaxis. The antigen induces IgE antibodies, which bind to most cells and basophils. Subsequent exposure to antigen causes binding with the cytophilic IgE resulting in the release of mediators. See allergy.
- tuberculin-type h. SYN: delayed reaction.

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hy·per·sen·si·tiv·i·ty (hi″pər-sen″sĭ-tivґĭ-te) a state of altered reactivity in which the body reacts with an exaggerated or inappropriate immune response to what is perceived to be a foreign substance. The resulting hypersensitivity reactions are usually subclassified as types I–IV on the basis of the Gell and Coombs classification of immune responses; see individual types under hypersensitivity reaction at reaction.

Medical dictionary. 2011.

Look at other dictionaries:

  • hypersensitivity — hypersensitivity. См. гиперчувствительность. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Hypersensitivity — NOTOC Infobox Disease Name = PAGENAME Caption = DiseasesDB = 28827 ICD10 = ICD10|T|78|4|t|66 ICD9 = ICD9|995.3 ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = MeshID = D006967 Hypersensitivity (also called hypersensitivity reaction)… …   Wikipedia

  • hypersensitivity — In immunology, a state of excessive and potentially damaging immune responsiveness as a result of previous exposure to antigen. If the hypersensitivity is of the immediate type (antibody mediated), then the response occurs in minutes; in delayed… …   Dictionary of molecular biology

  • hypersensitivity — See hypersensitiveness. * * *       acquired bodily state in which the reaction to a stimulus (e.g., a substance causing allergy or a physical agent such as light) is unusually prompt or excessive. The term hypersensitivity is often used as a… …   Universalium

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  • hypersensitivity — noun 1. pathological sensitivity • Derivationally related forms: ↑hypersensitive • Hypernyms: ↑sensitivity, ↑predisposition • Hyponyms: ↑cryesthesia, ↑cryaesthesia, ↑ …   Useful english dictionary

  • hypersensitivity — noun see hypersensitive …   New Collegiate Dictionary

  • hypersensitivity — (hi per sen si tiv i te) A condition of increased immune sensitivity in which the body reacts to an antigen with an exaggerated immune response that usually harms the individual. Also termed an allergy …   Dictionary of microbiology

  • hypersensitivity — noun any heightened immune response to an antigen; an allergy See Also: hypersensitive …   Wiktionary

  • hypersensitivity — Synonyms and related words: allergy, anaphylaxis, considerateness, delicacy, empathy, exquisiteness, fineness, hairsplitting, hypercriticism, hyperesthesia, hyperpathia, hypersensitiveness, identification, irritability, morbid sensibility,… …   Moby Thesaurus

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