Acute Caremiddle twist
A 63-year-old man wakes at 5 am with swelling of his lower lip and the left side of his tongue. There is no rash and nothing itches. His voice is normal, his chest is clear and his blood pressure is 148/86 mmHg. He ate his usual dinner and has had no sting. He has taken perindopril for four years and atorvastatin for two months, and nothing else. He has never had swelling before and no one in his family has. The ambulance crew gave adrenaline 500 micrograms intramuscularly on the way in and the swelling is unchanged. Which one of the following best explains his swelling?