hypersensitivity reaction

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Related to hypersensitivity reaction: delayed hypersensitivity reaction


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 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·tion

a 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).

al·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 reaction

Q. 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:

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:

More discussions about hypersensitivity reaction
References in periodicals archive ?
Tsur and Kalansky (9) reported that sugammadex-induced hypersensitivity reactions were observed in the first 5 min of administration.
NSAIDs can also induce immunological (noncross-reactive) hypersensitivity reactions, including IgE-mediated single-NSAID-induced urticaria/angioedema or anaphylaxis (SNIUAA), and T cell-mediated single-NSAID-induced delayed hypersensitivity reactions (SNIDHR).
- Hev proteins found within natural rubber latex cause type I (IgE mediated) hypersensitivity reaction and allergic anaphylaxis.
5%.1 SJS is named after two American pediatricians Albert Mason Stevens and Frank Chambliss Johnson who jointly published the first description of the disorder in the American Journal of Diseases of Children in 1922.2 Stevens-Johnson Syndrome (SJS) is an immune-complex-mediated hypersensitivity reaction that characteristically involves skin and mucous membrane.
* Describe hypersensitivity reactions and their classifications.
" Hypersensitivity reactions to mango are distinctly uncommon, especially in India.
While testing the reaction to household allergens, moderate positive immediate hypersensitivity reaction was caused by the dog fur in 66.6% of patients.
It is fundamental to allogeneic- and synergeneic-graft rejection, graft-versus-host reactions and the delayed hypersensitivity reactions [10,21].
We suspect that either an immediate Type 1 hypersensitivity reaction occurred or a contaminant was present, resulting in the fatalities of these elf owls.
No one had taken antiretrovirals before the study, and everyone had a negative test for the gene that signals a hypersensitivity reaction to Ziagen.
It has been suggested by experts that asthma in cats is allergic in nature and similar to human allergic asthma that is caused by a hypersensitivity reaction to inhaled aeroallergens.
Researchers induced contact hypersensitivity reaction with oxazolone, a chemical allergen used for immunological experiments and found that bortezomib significantly inhibited the contact hypersensitivity responses.