Necrobiosis lipoidica (NL) is a chronic granulomatous dermatitis typically localized to the shins and associated with diabetes mellitus (DM). While various authorities consider NL to be primarily a disease of collagen degeneration or a vasculopathy, its exact etiology and pathogenesis remain unknown.
The local Department of Neurology requested a dermatology consultation on a 56-year-old woman with a recent stroke and itchy plaques on her legs that had slowly increased in size since 1986. Physical examination showed yellow-brown, atrophic plaques surrounded by raised, violaceous rims and occupying most of both shins (Figure, A). Similar smaller lesions were also present on the calves and on the right thigh. Her medical history was remarkable for newly diagnosed type 2 DM and arterial hypertension.
Shimanovich I, Erdmann H, Grabbe J, Zillikens D, Rose C. Necrobiosis Lipoidica in Monozygotic Twins. Arch Dermatol. 2008;144(1):119-120. doi:10.1001/archdermatol.2007.26