Anaphylaxis and Hypersensitivity Reactions

pp 33-46


Pathophysiology and Organ Damage in Anaphylaxis

  • Stephen F. KempAffiliated withUniversity of Mississippi Medical Center Email author 
  • , Richard F. Lockey

* Final gross prices may vary according to local VAT.

Get Access


Anaphylaxis is an acute, potentially life-threatening multisystem syndrome resulting from the sudden release of mast cell- and basophil-derived mediators into the systemic circulation. Foods, medications, and insect stings cause most anaphylaxis for which a cause can be identified, but virtually any agent capable of directly or indirectly activating mast cells or basophils can cause it. This syndrome can consist of some or all the following signs and symptoms: diffuse pruritus, erythema, urticaria, and/or angioedema; bronchospasm; laryngeal edema; hypotension; and/or cardiac arrhythmias. Some of the other symptoms that can occur include nausea, vomiting, diarrhea, lightheadedness, headache, feeling of impending doom, and unconsciousness. Regardless of the presenting signs or symptoms, which usually present within 5–30 min following the administration of the offending agent, this reaction can progress to respiratory compromise and cardiovascular collapse resulting in human fatalities. Usually, the more rapid the onset of clinical manifestations, the more likely the anaphylaxis will be life threatening. Immediate and appropriate therapy, especially with epinephrine, is mandatory to reverse the reactions. While most reactions are uniphasic, some can be biphasic or protracted. This chapter discusses the immunopathologic mechanisms and effects of anaphylaxis.


Anaphylaxis Pathophysiology Severe allergic reactions Systemic allergic reactions