A 22-year-old man comes to the emergency department because of the onset of facial swelling, difficulty breathing 20 minutes after eating some trail mix. He has never had a similar episode before. Blood pressure is 80/40 mm Hg, pulse is 130/min, and respirations are 32/min. Examination shows generalized hives, swelling of his tongue and lips, and labored breathing with intercostal retractions. Intravenous fluids are begun, and intramuscular epinephrine is administered immediately. In addition to its effect on airway and circulation, this medication is most likely to improve this patient's condition through which of the following mechanisms?

Question

A 22-year-old man comes to the emergency department because of the onset of facial swelling, difficulty breathing 20 minutes after eating some trail mix. He has never had a similar episode before. Blood pressure is 80/40 mm Hg, pulse is 130/min, and respirations are 32/min. Examination shows generalized hives, swelling of his tongue and lips, and labored breathing with intercostal retractions.   Intravenous fluids are begun, and intramuscular epinephrine is administered immediately.  In addition to its effect on airway and circulation, this medication is most likely to improve this patient's condition through which of the following mechanisms?

Quizplus · Accepted Answer

Eductional Objective: Anaphylaxis is a type 1 (immediate) hypersensitivity reaction involving IgE-mediated mast cell and basophil degranulation.  Epinephrine is the primary treatment for anaphylaxis because it decreases further mast cell release of inflammatory mediators and counteracts existing systemic inflammatory effects (eg, shock, bronchoconstriction).

A 22-Year-Old Man Comes to the Emergency Department Because of the Onset