https://doi.org/10.1351/goldbook.12871
Immediate overreaction of the immune system to a drug or other agent in an individual who has previously encountered the agent and has produced antibodies to that agent.
Note: The major manifestation of anaphylactic shock is angioedema, which leads to hypovalemia, obstruction of the airway, and bronchospasm; these in turn may lead to coma or death.
See also: anaphylaxis