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Fig. 36.1 Necrobiosis lipoidica diabeticorum. A, Typical yellow-red plaque of a developed lesion. B, Late lesion with central atrophy and extensive ulceration. (Courtesy of James E. Fitzpatrick, MD.) |
This disease is characterized by granulomatous inflammation and fibrosis with a marked predilection to occur on the pretibial areas, although it may occur at other sites. Early lesions present as nondiagnostic erythematous papules and evolve into annular lesions that have a yellowish-brown color, dilated blood vessels, and central epidermal atrophy (Fig. 36-1). Fully developed pretibial lesions can be diagnosed by clinical appearance.