Idiopathic atrophie blanche.

Idiopathic atrophie blanche (segmental hyalinizing vasculitis; livedo reticularis with summer ulceration) is a chronic cutaneous disorder of young to middle-aged women that is characterized by persistent painful leg ulcerations. Primary lesions consist of purpuric macules and papules which undergo superficial ulceration, followed eventually by the development of irregular, atrophic, porcelain white scars with fine borders of ectatic vessels. We have studied twelve patients with idiopathic atrophie blanche by immunofluorescence, thin section light microscopy, and electron microscopy. All patients were examined extensively in order to rule out primary immunologic and vaso-occlusive disorders that may result in a similar clinical appearance. Subsequently, ten patients were treated for 1 to 12 years with combinations of phenformin and ethylestrenol. Each treated patient noted rapid improvement in existing lesions, significantly less pain, and a decrease in the development of new lesions. Side effects in all but two patients were minimal and well tolerated. Light and electron microscopic examination of early and well-developed lesions revealed fibrin plugs which first occlude superficial dermal vessels, followed by necrosis and obliteration of the affected vessel walls. Eventually, new vessel formation occurs in some areas of fibrin deposition. Polymorphonuclear leukocytes and mononuclear cells only rarely participate in this process. Although this disorder has previously been considered a localized form of cutaneous vasculitis, the absence of both leukocytes and nuclear fragmentation from the neighborhood of vascular structures in early lesions differentiates this disorder from immune complex-mediated necrotizing vasculitis. Thus the term vasculopathy describes this disorder more appropriately than the term vasculitis.