A 25-year-old man comes to an outpatient clinic complaining of low-grade fever and sore throat. He receives an injection of intramuscular penicillin for presumed streptococcal pharyngitis. He is otherwise healthy and takes no regular medications. Within 20 minutes, he begins to complain of swelling of his face and difficulty breathing. He looks dyspneic and frightened. His heart rate is 130 bpm, blood pressure 90/47 mm Hg, and respiratory rate 28 breaths per minute and shallow. His face and lips are edematous and he can barely open his eyes because of swelling.
He is wheezing diffusely and has multiple raised urticarial lesions on his skin. An ambulance has been called. What is the most likely diagnosis in this case? What will be your next step? *This patient case is from Docplexus Editorial Team for educative purpose only. Source: Case Files Internal Medicine
