A 65-year-old woman is referred to dermatology with discoloration of her legs that started several weeks ago. Her family suggested it might be “blood clots,” although she has been taking warfarin since she was diagnosed with atrial fibrillation several months ago. Her dermatologic condition is basically asymptomatic, but the patient admits to scratching her legs, saying it’s “hard to leave them alone.” On further questioning, she reveals that she has had “rough places” on her legs for at least 20 years and volunteers that her sister had the same problem, which was diagnosed years ago as “fungal infection.” Both she and her sister spent a great deal of time in the sun as children, long before sunscreen was invented. The patient is otherwise fairly healthy. She takes medication for her lipids, as well as daily vitamins. Her atrial fibrillation is under control and requires no medications other than the warfarin. A great deal of focal discoloration is seen on both legs, circumferentially distributed from well below the knees to just above the ankles. Many of the lesions are brown macules, but more are purplish-red, annular, and scaly. On closer examination, these lesions—the ones the patient says she has had for decades—have a very fine, thready, scaly border that palpation reveals to be tough and adherent. They average about 2 cm in diameter. There are no such lesions noted elsewhere on the patient’s skin. There is, however, abundant evidence of excessive sun exposure, characterized by a multitude of solar lentigines, many fine wrinkles, and extremely thin arm skin.
