A 58-year-old woman presents to dermatology with a 15-year history of an itchy rash on her left leg. A native of India, she has been in this country for more than 20 years and enjoys generally good health.
But about 15 years ago, she experienced some personal problems that caused great stress. About that same time, she developed a small rash on her left leg, which she began to scratch.
Over time, the lesion has become larger and more pruritic, prompting her to scratch and rub it more. Lately, she has started to use a hairbrush to scratch it. The itching has taken on a whole new level of intensity.
Her primary care provider referred her to a wound care clinic, where her lesion was treated with twice-weekly whirlpool therapy, followed by debridement and dressing with a zinc oxide–based paste. Although this calmed the affected site a bit, when treatment ceased, the rash flared again.
EXAMINATION
The patient has type IV skin, consistent with her origins. The lesion is an impressive, elongated oval plaque measuring about 20 x 10 cm. It covers most of the anterolateral portion of her left leg and calf.
An underlying area of brown macular hyperpigmentation extends an additional 2 to 3 cm around the periphery of the plaque. The central area is slightly edematous, quite pink, and shiny. No focal breaks in the skin are observed. There is no increased warmth or tenderness on palpation.
What is the diagnosis?