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hypersensitivity reaction
Thesaurus| Noun | 1. | hypersensitivity reaction - 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 shockhives, 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 drugsallergic reaction, allergy - hypersensitivity reaction to a particular allergen; symptoms can vary greatly in intensityanaphylaxis - hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with a substancehypersensitivity - pathological sensitivityallergic rhinitis - rhinitis caused by an allergic reaction |
EncyclopediaSeehypersensitivityhypersensitivity reaction
hypersensitivity [hi″per-sen″sĭ-tiv´ĭ-te] a state of altered reactivity in which the body reacts with an exaggerated immune response to a foreign agent; anaphylaxis and allergy are forms of hypersensitivity. The hypersensitivity states and resulting reactions" >hypersensitivity reactions are usually subclassified by the Gell and Coombs classification. adj., adj hypersen´sitive.contact hypersensitivity that produced by contact of the skin with a chemical substance having the properties of an antigen or hapten.delayed hypersensitivity (DH) (delayed type hypersensitivity (DTH)) the type of hypersensitivity exemplified by the tuberculin reaction, which (as opposed to immediate hypersensitivity) takes 12 to 48 hours to develop and which can be transferred by lymphocytes but not by serum. Delayed hypersensitivity can be induced by most viral infections, many bacterial infections, all mycotic infections, and a few protozoal infections (leishmaniasis and toxoplasmosis). The scope of the term is sometimes expanded to cover all aspects of cell-mediated immunity including contact dermatitis, granulomatous reactions, and allograft rejection.immediate hypersensitivity antibody-mediated hypersensitivity occurring within minutes when a sensitized individual is exposed to antigen; clinical manifestations include systemic anaphylaxis and atopic allergy (allergic rhinitis, asthma, dermatitis, urticaria, and angioedema). The first exposure to the antigen induces the production of IgE antibodies (cytotropic antibodies, reagin) that bind to receptors on mast cells and basophils. Subsequent exposure to the antigen triggers production and release of a diverse array of mediators of hypersensitivity that act on other cells producing symptoms such as bronchospasm, edema, mucous secretion, and inflammation.hypersensitivity reaction the exaggerated or inappropriate immune response occurring in hypersensitivity, in response to a substance either foreign or perceived as foreign and resulting in local or general tissue damage. Such reactions are usually classified as types I–IV on the basis of the Gell and Coombs classification.al·ler·gic re·ac·tiona local or general reaction of an organism following contact with a specific allergen to which it has been previously exposed and sensitized; immunologic mechanisms gives rise to inflammation or tissue damage. Allergic reactions are classified into four major types: type I, anaphylactic and IgE dependent; type II, cytotoxic; type III, immune-complex mediated; type IV, cell mediated (delayed). Synonym(s): hypersensitivity reactional·ler·gic re·ac·tion (ă-lĕr'jik rē-ak'shŭn) Local or general reaction of an organism after contact with a specific allergen to which it has been previously exposed and sensitized.
Synonym(s): hypersensitivity reaction. Patient discussion about hypersensitivity reactionQ. ALLERGIES what are they,who gets them,are they caused by pollen and food?A. Allergy is the exaggerated and out-of-place reaction of the immune system to external substances or stimuli that are not harmful to the body, so the reaction actually damages the body instead of helping it.
The may be pollen and foods, as well as insect stings, drugs and almost any other substances.
You may read more here:
www.nlm.nih.gov/medlineplus/allergy.html
http://www.mayoclinic.com/health/allergy/AA99999
Q. what is the most common allergy? is it dust allergy?A. thanks, I've heard of a new allergy treatment and trying to learn some more about the different kinds... Q. what are the symptoms of Allergy? A. from you question i understand that you think you might developed an allergy. so here is a web page with couple of videos explaining about allergies:
http://www.healthline.com/video/allergies
More discussions about hypersensitivity reactionFinancialSeeReactionhypersensitivity reaction
Related to hypersensitivity reaction: delayed hypersensitivity reactionWords related to hypersensitivity reactionnoun an inappropriate and excessive reaction to an allergen (as pollen or dust or animal hair or certain foods)Related Words- hives
- nettle rash
- urticaria
- urtication
- allergic reaction
- allergy
- anaphylaxis
- hypersensitivity
- allergic rhinitis
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