Dermatologymiddle twist
A 34-year-old man started lamotrigine 16 days ago for newly diagnosed epilepsy. For three days he has had fever, sore eyes and painful mouth ulcers that make swallowing difficult. Today a rash appeared on his trunk and face: dusky red, painful flat spots, some with a dark centre, several forming flaccid blisters. When the skin at the edge of a blister is rubbed gently the top layer slides off, leaving a raw red base. His temperature is 38.9 °C. About 8% of his body surface is involved. The lips are crusted and the conjunctivae are red.
Which one of the following is the most likely diagnosis?