anaphylaxis: meaning, definition, pronunciation and examples
C2Technical / Medical
Quick answer
What does “anaphylaxis” mean?
A severe, rapid, and potentially life-threatening allergic reaction to a substance (allergen), often causing difficulty breathing, a sudden drop in blood pressure, and loss of consciousness.
Audio
Pronunciation
Definition
Meaning and Definition
A severe, rapid, and potentially life-threatening allergic reaction to a substance (allergen), often causing difficulty breathing, a sudden drop in blood pressure, and loss of consciousness.
The term can be used more broadly in medical literature to describe any acute, systemic hypersensitivity reaction, including severe immune responses to drugs, insect venom, or foods. It can also appear metaphorically in non-medical contexts to describe an extreme, sudden negative reaction to an event or idea.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or semantic differences. Both varieties use the term identically in medical contexts.
Connotations
Identical connotations of medical urgency and severity in both dialects.
Frequency
Equally low-frequency and specialised in both UK and US English, confined primarily to medical and healthcare discourse.
Grammar
How to Use “anaphylaxis” in a Sentence
suffer from anaphylaxis (to + allergen)experience anaphylaxisanaphylaxis is triggered by Xanaphylaxis caused by Xtreat for anaphylaxisVocabulary
Collocations
Examples
Examples of “anaphylaxis” in a Sentence
verb
British English
- The patient anaphylaxed after the antibiotic dose.
- She is at risk of anaphylaxing if exposed to latex.
American English
- The patient anaphylaxed following the contrast injection.
- Individuals can anaphylax within minutes of exposure.
adverb
British English
- The patient reacted anaphylactically to the first dose.
American English
- The drug can cause a reaction that presents anaphylactically.
adjective
British English
- He carries an anaphylactic pen for emergencies.
- They administered adrenaline for the anaphylactic response.
American English
- She carries an epinephrine auto-injector for anaphylactic emergencies.
- The anaphylactic shock required immediate intervention.
Usage
Meaning in Context
Business
Virtually never used. Might appear only in pharmaceutical/healthcare company risk assessments or drug information leaflets.
Academic
Primarily in medical, biological, and pharmacological research papers, textbooks, and lectures.
Everyday
Extremely rare outside of conversations about specific, severe allergies. Parents of children with severe allergies or individuals with conditions like mastocytosis might use it.
Technical
The primary domain of use. Found in clinical notes, emergency medicine protocols, allergy and immunology literature, and medical training.
Vocabulary
Synonyms of “anaphylaxis”
Vocabulary
Antonyms of “anaphylaxis”
Watch out
Common Mistakes When Using “anaphylaxis”
- Misspelling as 'anaphylatic' or 'anaphylaxsis'.
- Incorrect pronunciation with stress on the third syllable: /ˌænəfɪˈlæksɪs/ is correct, not /ˈænəfɪlæksɪs/.
- Using it to refer to any mild allergic reaction (e.g., hay fever).
FAQ
Frequently Asked Questions
Anaphylaxis is systemic (affects the whole body), rapid, and involves potentially life-threatening symptoms like airway constriction and low blood pressure. A mild reaction, like hives or a runny nose, is usually localised and not dangerous.
The first-line and most critical treatment is an immediate intramuscular injection of epinephrine (adrenaline). This should be followed by calling emergency services, as further treatment and observation in a hospital are often required.
Typically, no. Anaphylaxis requires prior sensitisation, where the immune system has been exposed to the allergen before and created IgE antibodies. The severe reaction occurs upon a subsequent exposure.
Anaphylactic shock is a severe subset of anaphylaxis where there is a profound drop in blood pressure (shock) leading to inadequate blood flow to organs. All anaphylactic shock is anaphylaxis, but not all anaphylaxis progresses to shock.
A severe, rapid, and potentially life-threatening allergic reaction to a substance (allergen), often causing difficulty breathing, a sudden drop in blood pressure, and loss of consciousness.
Anaphylaxis is usually technical / medical in register.
Anaphylaxis: in British English it is pronounced /ˌænəfɪˈlæksɪs/, and in American English it is pronounced /ˌænəfəˈlæksɪs/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None. The word is a technical medical term and does not feature in idiomatic expressions.”
Learning
Memory Aids
Mnemonic
Think: 'Ana' (against) + 'phylaxis' (protection) = the body's protection system turns severely *against* a harmless substance.
Conceptual Metaphor
Often framed as a **SYSTEM FAILURE** or **CASCADE** (e.g., 'the reaction cascaded into full-blown anaphylaxis') or as a **TRIGGERED ALARM** that cannot be turned off.
Practice
Quiz
Which of the following is the most accurate description of anaphylaxis?