RT Book, Section A1 Pattanaik, Debendra A1 Yataco, Jose C. A1 Lieberman, Phil A2 Hall, Jesse B. A2 Schmidt, Gregory A. A2 Kress, John P. SR Print(0) ID 1107714617 T1 Anaphylactic and Anaphylactoid Reactions T2 Principles of Critical Care, 4e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071738811 LK accessanesthesiology.mhmedical.com/content.aspx?aid=1107714617 RD 2024/10/10 AB Anaphylaxis is an acute life-threatening systemic reaction that results from sudden systemic release of mediators from mast cells and basophils.Degranulation of mast cell and basophils are commonly mediated by IgE antibody. Other nonimmunologic mechanisms including direct activation of these cells have been described.The incidence of anaphylaxis appears to be rising, especially among young people.Foods followed by medications (eg, antibiotics and NSAIDs) are the most common cause of anaphylaxis in the outpatient setting.Medications, for example, antibiotics, muscle relaxants, blood products, and radiocontrast media, are common causes of anaphylaxis in the hospital.Onset of symptoms of anaphylaxis is usually immediate but can be delayed by 2 to 10 hours.Cutaneous symptoms are common but hemodynamic collapse and shock can occur in the absence of skin manifestations.The hemodynamic symptoms of anaphylaxis are secondary to the widespread vasodilation and profound intravascular fluid loss.Careful history and physical examination are most important in the diagnosis of anaphylaxis. Measurement of serum tryptase and histamine can be helpful.Prompt recognition, administration of epinephrine, and intravascular volume replacement are key factors in the successful outcome of this potentially fatal event.