Necrobiosis lipoidica presenting as unilateral papulovesicular eruptions on the lower leg

Necrobiosis lipoidica is a chronic granulomatous disease that has a well-known association with diabetes mellitus. It usually affects the bilateral lower legs of middle-aged women. Over time, the clinical features vary from red-brown papules to sharply demarcated yellow-brown plaque with atrophic center. Some of the lesions may become ulcerated, especially in diabetic patients. A 61-year-old Korean female with a history of diabetes, ischemic heart disease, and pancreatic cancer was referred to our clinic for evaluation of the painful papulovesicles on her left lower leg. Under the assumptive diagnosis of herpes zoster, we immediately started an antiviral agent. However, her skin lesions rapidly increased in size and in number, and progressed to the multiple ulcerations in 9 days. Histopathologic examination showed several poorly circumscribed necrobiotic granulomas in the deep dermis and subcutis levels of the skin. In addition, prominent vascular ectasia and vasculitis were observed. We diagnosed the patient as having necrobiotic lipoidica, and treated her with oral dapsone, colchicine, phentoxifylline and antiplatelets. Her leg ulcerations healed after four weeks of treatment.