systemic anaphylaxis

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Related to systemic anaphylaxis: Anaphylactoid reactions

gen·er·al·ized an·a·phy·lax·is

(jen'ĕr-ă-līzd an'ă-fi-lak'sis)
The immediate response, involving smooth muscles and capillaries throughout the body, which follows injection of antigen (allergen).
See also: anaphylactic shock
Synonym(s): systemic anaphylaxis.

systemic anaphylaxis

A reaction between IgE antibodies bound to mast cells and an allergen that causes the sudden release of immunological mediators in the skin, respiratory, cardiovascular, and gastrointestinal systems. The consequences may range from mild, e.g., itching, hives, to life-threatening (airway obstruction and shock).
See also: anaphylaxis


an unusual or exaggerated allergic reaction of an animal to foreign protein or other substances. Anaphylaxis is an immediate or antibody-mediated hypersensitivity reaction (type I) produced by the release of vasoactive agents such as histamine and serotonin. Release is a consequence of the binding of IgE antibodies to Fc receptors on the surface of particularly mast cells and basophils. Antigen binding to two adjacent IgE molecules causes perturbation of the cell membrane leading to the release of vasoactive substances. Anaphylaxis may be localized, usually cutaneous, or generalized. Called also anaphylactic shock.
Substances most likely to produce anaphylaxis include drugs, particularly antibiotics and local anesthetics; drugs prepared from animals, such as insulin, adrenocorticotropic hormone and enzymes; diagnostic agents, such as iodinated x-ray contrast media; biologicals used to provide immunity, such as vaccines, antitoxins and gamma globulin; protein foods; the venom of bees, wasps and hornets; and pollens and molds. See also hypersensitivity, anaphylactic.

acquired anaphylaxis
that in which sensitization is known to have been produced by administration of a foreign antigen.
active anaphylaxis
see acquired anaphylaxis (above).
aggregate anaphylaxis
caused by large amounts of antibody-antigen complexes that activate complement and resulting in degranulation of mast cells.
antiserum anaphylaxis
passive anaphylaxis.
cutaneous anaphylaxis
a localized form of anaphylaxis, which follows the injection of antigen into the skin.
cytotoxic anaphylaxis
a form of anaphylaxis triggered by antibodies against self antigens. Blood transfusion reactions and Rh reactions are examples.
cytotropic anaphylaxis
refers to binding of IgE to Fc receptors.
heterologous anaphylaxis
passive anaphylaxis induced by transfer of serum from an animal of a different species.
homologous anaphylaxis
passive anaphylaxis induced by transfer of serum from an animal of the same species.
indirect anaphylaxis
that induced by an animal's own protein modified in some way.
passive anaphylaxis
that resulting in a normal animal from injection of serum of a sensitized animal.
passive cutaneous anaphylaxis (PCA)
localized anaphylaxis passively transferred by intradermal injection of an antibody and, after a latent period (about 24 to 72 hours), intravenous injection of the homologous antigen and Evans blue dye; blueing of the skin at the site of the intradermal injection is evidence of PCA.
reverse passive cutaneous anaphylaxis
antigen is injected first, succeeded by the injection of antiserum.
systemic anaphylaxis
a generalized anaphylactic reaction most often observed when the antigen is injected intravenously but may also be produced after local administration of antigen. The main shock organs in cattle and sheep are the lungs, in the horse, cat and pig the lungs and intestines, and in dogs the liver, specifically the hepatic veins.
References in periodicals archive ?
Drop in body temperature associated with systemic anaphylaxis were measured at time 0, 1 and subsequently every 5 min up to 90 min using a rectal probe coupled to a digital thermometer (AD Instruments, Castle Hill, Australia).
Histamine is believed to play a major role in vasodilation, vascular hyperpermeability and drop in body temperature during systemic anaphylaxis (Yoko et al.
Opiate antagonists reverse the hypoactivity associated with systemic anaphylaxis in mice.

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