anaphylactoid reaction

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Related to anaphylactoid reaction: anaphylaxis, Anaphylactic reaction


resembling anaphylaxis.
anaphylactoid reaction a reaction resembling generalized anaphylaxis but not caused by IgE-mediated allergic reaction but rather by a nonimmunologic mechanism.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

anaphylactoid reaction

An anaphylaxis-like reaction that occurs without an allergen-IgE antibody event, caused by a nonimmune release (e.g., reaction to radiocontrast, opiates, vancomycin, chymopapain, aspirin) of vasoactive and inflammatory mediators, including histamine.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

anaphylactoid reaction

(an″ă-fĭ-lak′′toyd″) [ anaphylact(ic) + -oid]
A reaction that resembles anaphylaxis, e.g., by hives, laryngeal edema, or shock, but does not involve IgE antibodies or allergens and therefore is has no allergic basis.


This relatively uncommon type of reaction can be caused by exercise; as the result of the release of histamine when body temperature rises; by elevated endorphin levels; by ionic compounds such as contrast media that contain radiographic iodine or polymyxin B antibiotic; by solutions containing polysaccharides such as dextran; by morphine, codeine, or meperidine; and by NSAIDs. The term should not be used as a synonym for mild anaphylaxis produced by IgE-allergen reactions.


Anaphylactoid reactions produce hives and itching identical to those of anaphylaxis. Very rarely, severe anaphylaxis or anaphylactic shock occurs. Anaphylactoid reactions are treated with the same drugs used to treat anaphylaxis.

Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Barth et al (93) injected 100 mg of tramadol intravenously (a single dose often administered) into 13 healthy volunteers and looked for histamine release, systemic or cutaneous anaphylactoid reactions and changes in blood pressure, heart rate and electrocardiogram variables.
There are many agents that can cause anaphylaxis or anaphylactoid reactions. Drugs are the leading cause for anaphylaxis, the major ones being antibiotics, seizure medicines, muscle relaxants, and certain postsurgery fluids.
Intradermal testing after anaphylactoid reaction to anaesthetic drugs, practical aspects of performance and interpretation.
Anaphylactoid reaction to intravenous contrast in patient with systemic mastocytosis.
Anaphylactoid reaction to administration of iodinated contrast media is a well known phenomenon.
This was a retrospective analysis of patients referred between June 2000 and February 2007 to the Immunology unit at the John Hunter Hospital for assessment after an anaphylactic or anaphylactoid reaction occurring during a general anaesthetic, as diagnosed by the anaesthetist managing the case.
Acetadote is contraindicated in patients with hypersensitivity or previous anaphylactoid reactions to acetylcysteine or any components of the preparation.
Incidence of anaphylactoid reactions to isosulfan blue dye during breast carcinoma lymphatic mapping in patients treated with preoperative prophylaxis: Results of a surgical prospective clinical practice protocol.
Anaphylactic and anaphylactoid reactions during anesthesia are major causes of concern for anesthesiologists (7).
FFP may result in anaphylactoid reactions, and like any plasma product carries an infectious transmission risk.
Reichen, "Anaphylactoid reactions after indocyanine-green administration," Annals of Internal Medicine, vol.