Emergency Medical Minute

Contributor: Aaron Lessen, MD Educational Pearls: What is anaphylaxis and what are its treatments?  Anaphylaxis is a broad term for potentially life threatening allergic reactions that can progress to cardiovascular collapse (anaphylactic shock).  It is triggered by IgE and antigen cross-linking on mast cells to induce degranulation and the release of histamines, which can cause diffuse vasodilation and respiratory involvement with end-organ hypoperfusion. First line treatment is the immediate administration of epinephrine at 0.01 mg/kg (max dose for pediatrics is 0.3 mg and for adults is 0.5 mg) as well as removal of the offending agent causing the reaction. Additional pharmacologic treatments such as anti-histamines and steroids should be considered but not used instead of epinephrine when anaphylactic shock is evident as the sole therapy. What is biphasic anaphylaxis and what is its occurrence? Biphasic anaphylaxis is the return of anaphylactic symptoms after the initial anaphylactic event. Previous stu