anaphylactic shock

American  

noun

1. Pathology. a severe and sometimes fatal allergic reaction to a foreign substance, especially a protein, as serum or bee venom, to which an individual has become sensitized, often involving rapid swelling, acute respiratory distress, and collapse of circulation.

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anaphylactic shock British  

noun

1. a severe, sometimes fatal, reaction to a substance to which a person has an extreme sensitivity, often involving respiratory difficulty and circulation failure

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anaphylactic shock Scientific  

/ ăn′ə-fə-lăk′tĭk /

1. A sudden, life-threatening allergic reaction, characterized by dilation of blood vessels with a sharp drop in blood pressure and bronchial spasm with shortness of breath. Anaphylactic shock is caused by exposure to a foreign substance, such as a drug or bee venom, to which the individual has been previously exposed. The substances act as antigens, provoking a preliminary immune response during the first exposure that results in a full-blown, immediate response during secondary exposure, called an immediate hypersensitivity reaction. Emergency treatment, including epinephrine injections, must be administered to prevent death.

2. Also called anaphylaxis

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Etymology

Origin of anaphylactic shock

First recorded in 1905–10

Compare meaning

How does anaphylactic-shock compare to similar and commonly confused words? Explore the most common comparisons:

• anaphylaxis vs. anaphylactic shock

Example Sentences

Such reactions can range from responses with “no clinical manifestations” to irritating rashes to life-threatening conditions such as anaphylactic shock, which constricts breathing and impairs motor function.

From Salon • Apr. 4, 2026

When my parents gave me that yellow M&M display in 2020, my throat tightened and my eyes welled up—not because I was going into anaphylactic shock but because I knew I was loved.

From The Wall Street Journal • Dec. 23, 2025

After he went into anaphylactic shock, Rex was quickly given his EpiPen and taken to hospital.

From BBC • Aug. 23, 2025

In Singapore, asthma affects one in five children while food allergies are already the leading cause of anaphylactic shock.

From Science Daily • Jun. 4, 2024

What do you say when your best friend has lost his mojo because you tried to reduce him to a paranoid bundle of nerves terrified of going into anaphylactic shock?

From "Liar, Liar" by Gary Paulsen