A 54-year-old female is brought to the Emergency Department by EMS after being stung by a “yellow jacket” while gardening. Within 10 minutes of the sting, she developed generalized itching and felt like her “throat was closing up.” She became lightheaded and collapsed to her knees. Her husband administered her prescribed epinephrine auto-injector immediately, but she reports no significant improvement. Her past medical history includes hypertension and migraine headaches. Her medications are atenolol and sumatriptan. She has no known drug allergies.

On arrival, she is anxious, diaphoretic, and struggling to speak in full sentences. She appears in acute distress, sitting in a tripod position with accessory muscle use. She is afebrile. Her blood pressure is 74/40 mmHg with a heart rate of 125 bpm. Her respiratory rate is 28 breaths per minute with an oxygen saturation of 88% on room air.