anaphylaxis

Borrowed from French anaphylaxie, coined by French physiologist and parapsychologist Charles Richet and by French zoologist Paul Portier from the Ancient Greek ᾰ̓νᾰ- (ănă-, “(intensifier) thoroughly”) from ᾰ̓νᾰ́ (ănắ, “to, again, upon”) and φύλαξις (phúlaxis, “protection, watching, guarding”).

anaphylaxis (countable and uncountable, plural anaphylaxes)

1. Extreme sensitivity to a substance such as a foreign protein or drug.
2. A severe and rapid systemic allergic reaction to an allergen, causing a constriction of the trachea, preventing breathing; anaphylactic shock.
   • 2024 August 9, Meg Tirrell, “First nasal spray epinephrine drug for emergency allergic reactions gets FDA approval”, in CNN‎^[1]:

     “Anyone who has experienced or witnessed an anaphylaxis reaction knows it can be very stressful deciding when to inject epinephrine to themselves or a child and often delay,” Dr. Jonathan Spergel, chief of the allergy program at Children’s Hospital of Philadelphia, said in a news release from ARS Pharmaceuticals.

   • 2025 August 16, Rylee Kirk, quoting William Sutton, “Hiker in Tennessee Who Picked Up a Venomous Snake Dies After Being Bitten”, in The New York Times‎^[2], New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 16 August 2025:

     He said a bite could send someone into anaphylaxis, which is a narrowing of the airways and lowering of blood pressure, within minutes.

• hypersensitivity
  • type I hypersensitivity