anaphylaxis

noun2

1. •
   A severe and rapid systemic allergic reaction to an allergen, causing a constriction of the trachea, preventing breathing; anaphylactic shock.

   • He said a bite could send someone into anaphylaxis, which is a narrowing of the airways and lowering of blood pressure, within minutes. — 2025
2. •
   Extreme sensitivity to a substance such as a foreign protein or drug.