A 17-year-old girl came to a dermatology clinic in Athens, Greece, with what looked like a worrying ulcer on her left ankle: a black center ringed by red skin, the classic look of a sore with dead tissue. She said the lesion had been there for 10 days and hurt so much that she had stopped going to school.
The answer came from an unlikely place. While a doctor wet the ankle with water to attach heart-monitor electrodes, the "ulcer" rinsed away. It had been drawn on with a marker.
