# anaphylaxis

/ˌænəfəˈɫæksɪs/ (US) · /ˌænɐfɪlˈæksɪs/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/anaphylaxis
Updated: 2026-10-19

## Definition

a very serious, sudden allergic reaction that can make breathing difficult and lower blood pressure. It needs emergency treatment right away.

For teachers: a severe, potentially life-threatening systemic hypersensitivity reaction with rapid onset, often involving airway compromise and cardiovascular collapse. Commonly triggered by foods, insect venom, or drugs.

## Examples

- Peanuts can trigger anaphylaxis in some people.
- After the bee sting, he shows signs of anaphylaxis, so his friend gives him an injection and calls emergency services.
- Despite strict avoidance measures, trace exposure to shellfish precipitated anaphylaxis, requiring intramuscular adrenaline and overnight observation to guard against a biphasic response.

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