Clinical immunology review series: an approach to the patient with anaphylaxis.

Anaphylaxis is a severe, life-threatening, generalized or systemic hypersensitivity reaction. While there is agreement as to this definition of anaphylaxis, the clinical presentation is often variable and it is not uncommon for there to be debate after the event as to whether anaphylaxis had actually occurred. The management of anaphylaxis falls into two distinct phases: (1) emergency treatment and resuscitation of a patient with acute anaphylaxis and (2) the search for a cause for the event and the formulation of a plan to prevent and treat possible further episodes of anaphylaxis. Both aspects are important in preventing death from anaphylaxis and are covered in this review.