Test your diagnostic skills in our regular dermatology quiz. What is this enlarging plaque on a woman’s leg, which has recently become painful?
A 52-year-old woman with insulin-dependent diabetes presents with a yellow-red telangiectatic plaque on the pretibial surface of her left leg (Figure). The lesion is well-demarcated, with an elevated peripheral violaceous rim, and gradually enlarging. The lesion was painless but recently began to erode centrally and has become painful.