Acute Caremiddle twist
A 62-year-old man wakes at 5 am with swelling of his lips and tongue that has worsened over three hours. He ate prawns and drank a glass of wine at a restaurant the previous evening. There is no rash, no itch and no flushing, he is not wheezing and his voice is normal. Blood pressure is 138/82 mmHg and pulse 76 beats per minute. He has taken perindopril for hypertension for four years and has never had swelling before; his parents and three siblings have never had similar attacks. There is no lymphadenopathy or splenomegaly. Which one of the following best explains his presentation?