Anaphylactic shock is an event triggered by the reintroduction of a microorganism which was previously well-tolerated in a first administration. The term anaphylaxis was first used in 1902 by Richet and Portier to describe, in dogs, the manifestations linked to the development of IgE dependent hypersensitivity reactions and their consequences, i.e. release of mediators such as histamine.
Two types of reactions are at the origin of anaphylactic shock:
- Anaphylactic reactions: triggered by an immune mechanism and presupposing a prior antigenicity.
- Anaphylactoid reactions: release of mediators from the body triggered by a non-immune mechanism and without prior antigenicity.
Clinical tables and management are, nevertheless, strictly the same regardless of thetriggering mechanism.
Anaphylactic shock is an Absolute Medical Emergency which
requires treatment with epinephrin as soon as there is a diagnosis
suggested.