immediate hypersensitivity


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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 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.

im·me·di·ate hy·per·sen·si·tiv·i·ty

an exaggerated immune response mediated by mast cell-bound IgE antibodies occurring within minutes after exposing a sensitized individual to the approximate antigen; also called Type I hypersensitivity. Clinical symptoms result from the physiologic effects of preformed or newly generated mediators, including histamine, platelet activating factor, prostaglandins, leukotrienes, bradykinin, tachykinins, and others. The reaction may be localized to specific organ systems or be generalized, leading to anaphylaxis. Symptoms include pruritus, urticaria, angioedema, conjunctivitis, sneezing, rhinorrhea, bronchospasm, hypotension, arrhythmias, and shock. See: allergy.

immediate hypersensitivity

Immediate hypersensitivity reaction Immunology An event unleashed by cross-linking of IgE antibodies on the surfaces of mast cells and basophils, after exposure to an allergen to which a person has been previously sensitized, resulting in release of histamine and related compounds

im·me·di·ate hy·per·sen·si·tiv·i·ty

(i-mēdē-ăt hīpĕr-sen-si-tivi-tē)
Exaggerated immune response mediated by mast cell-bound immunoglobulin E antibodies occurring within minutes after exposing a sensitized individual to the approximate antigen; also called Type I hypersensitivity.

im·me·di·ate hy·per·sen·si·tiv·i·ty

(i-mēdē-ăt hīpĕr-sen-si-tivi-tē)
An exaggerated immune response mediated by mast cell-bound IgE antibodies occurring within minutes after exposing a sensitized patient to the approximate antigen; also called Type I hypersensitivity.
References in periodicals archive ?
Development and extent of the immediate hypersensitivity reaction changes with the progression of HIV/AIDS despite the high level of IgE in infected patients compared to the control group.
Blanca et al., "Genetic variants associated with drugs-induced immediate hypersensitivity reactions: a PRISMA-compliant systematic review," Allergy, vol.
Cristaudo et al., "Urticaria from beer: an immediate hypersensitivity reaction due to a 10-kDa protein derived from barley," Clinical and Experimental Allergy, vol.
Immediate hypersensitivity reactions are mediated by IgE class antibodies and occur within 30 minutes of exposure to the causative agent.
Two types of hypersensitivity are described with LAs--the relatively more common contact delayed hypersensitivity, mainly related to ester-LAs, and the less common immediate hypersensitivity associated with ester-LAs and exceptionally with amide-LAs.
The clinical severity of immediate hypersensitivity reactions in the perioperative period have been graded (Table).8
Zacharisen et al.8 reported two patients with immediate hypersensitivity reaction to tomato in the form of laryngeal edema.
Type I reactions: These are mediated by IgE antibodies and are also known as immediate hypersensitivity reactions.
Atopy is a syndrome characterized by immediate hypersensitivity reactions to common environmental antigens.
Various immunologic responses are provoked, including immediate hypersensitivity reactions (Gross and Halliwell, 1985) late phase IgE-mediated responses and cutaneous basophil hypersensitivity reactions (Halliwell et al., 1987) and not delayed hypersensitivity (Reedy et al., 2003).
"PPD is implicated in allergic contact dermatitis, but also in immediate hypersensitivity reactions, and it has been implicated as a possible risk factor for a number of cancers," he added.
The good news: The incidence of type I immediate hypersensitivity to latex protein among health care workers appears to be declining.

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