immunology allergic disorders
Anaphylaxis
Pathophysiology of Anaphylaxis
Interaction of antigen with IgE on basophils and mast cells triggers release of histamine, leukotrienes, and other mediators that cause diffuse smooth muscle contraction (eg, resulting in bronchoconstriction, vomiting, or diarrhea) and vasodilation with plasma leakage (eg, resulting in Urticaria or Anaphylactoid reactions are clinically indistinguishable from anaphylaxis but do not involve IgE and do not require prior sensitization. They occur via direct stimulation of mast cells or via immune complexes that activate complement. The most common triggers of anaphylactoid reactions are Iodinated radiopaque contrast agents Aspirinand other nonsteroidal anti-inflammatory drugs (NSAIDs) Opioids Monoclonal antibodies Exercise 