1) Anaphylaxis is a severe allergic reaction that can cause death within minutes if not treated quickly, affecting approximately 2 million Americans annually and causing 400-800 deaths. 2) Allergic reactions are caused by the immune system releasing chemicals to fight foreign substances (antigens) that can cause symptoms ranging from mild irritation to constricted airways and shock. 3) Epinephrine auto-injectors like EpiPens can prevent death from anaphylaxis if administered promptly by injecting the drug into the outer thigh upon onset of symptoms like low blood pressure, swelling of the face/throat, difficulty breathing, and shock.