2023 Jan 26. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–.
Anaphylaxis is a common medical emergency and a life-threatening acute hypersensitivity reaction. It can be defined as a rapidly evolving, generalized, multi-system allergic reaction. Without treatment, anaphylaxis is often fatal due to its rapid progression to respiratory collapse. Historically, anaphylactic reactions were categorized as IgE-mediated responses, while anaphylactoid reactions were categorized as IgE-independent events. Recently, these terms have been consolidated into a single diagnosis of anaphylaxis. Regardless of causation, the resultant clinical state and treatment for each reaction are identical; therefore, this unified terminology is currently the accepted vernacular.