Food allergies, particularly to peanuts, are a common cause of anaphylaxis. Approximately 125 people die each year in the USA secondary to food-induced anaphylaxis. Clinical anaphylaxis is a syndrome of diverse etiology and dramatic presentation of symptoms associated with the classic features of type I, IgE-mediated hypersensitivity [1]. Typically the term anaphylaxis connotes an immunologically-mediated event that occurs after exposure to certain foreign substances. This reaction results from the generation and release of a variety of potent biologically active mediators and their concerted effects on various target organs. Anaphylaxis is recognized by cutaneous, respiratory, cardiovascular, and gastrointestinal signs and symptoms occurring singly or in combination. This article focuses on allergic reactions to peanuts that manifest as signs and symptoms involving multiple target organs or the cardiovascular system alone.