Anaphylaxis is a severe, acute, life‐threatening generalized or systemic hypersensitivity reaction. The incidence of anaphylaxis is increasing worldwide, with medications and food contributing to most cases. Physical exercise, acute infections, drugs, alcohol, and menstruation are the external cofactors associated with more severe systemic reaction. The aim of this review is to show that platelet‐activating factor contributes to the development of severe anaphylactic reaction, and even to anaphylactic shock.