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anaphylaxis

American  
[an-uh-fuh-lak-sis] / ˌæn ə fəˈlæk sɪs /

noun

Pathology.
  1. exaggerated allergic reaction to a foreign protein resulting from previous exposure to it.


anaphylaxis British  
/ ˌænəfɪˈlæksɪs /

noun

  1. extreme sensitivity to an injected antigen, esp a protein, following a previous injection

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

anaphylaxis Scientific  
/ ăn′ə-fə-lăk′sĭs /

Other Word Forms

Etymology

Origin of anaphylaxis

First recorded in 1905–10; ana- + (pro)phylaxis

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

He said his wife discovered her allergy only this spring when she “turned red as an Oompa Loompa” and went into anaphylaxis two hours after eating a hamburger.

From Los Angeles Times ● Oct. 4, 2026

Baxter was not given anti-venom over concerns about his breathing and possible side effects, which can include anaphylaxis.

From BBC ● Apr. 24, 2026

The results also pointed to an extreme immune response consistent with fatal anaphylaxis.

From Science Daily ● Dec. 17, 2025

The immune system tries to fight them off, triggering symptoms ranging from hives and diarrhea to anaphylaxis, a life-threatening condition.

From Los Angeles Times ● Oct. 20, 2025

May not the phenomena of anaphylaxis be studied on associational lines?

From Origin and Nature of Emotions by George W. (Washington) Crile

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