A 10-year-old boy with no significant past medical history is brought to the emergency department after eating shrimp at a restaurant. Within minutes, he developed swelling of the lips, hives on his chest and arms, and difficulty breathing. His parents state that he also complained of a “tight throat” and dizziness. On physical examination, he has facial edema, audible stridor, and hypotension (BP: 80/50 mmHg). What is the most appropriate immediate treatment?
