Necrolytic acral erythema.

Necrolytic acral erythema (NAE) is a recently recognized dermatosis almost exclusively associated with hepatitis C virus (HCV) infection and closely related to a group of necrolytic erythemas and metabolic syndromes. NAE is characterized by pruritic, symmetric, well-demarcated, hyperkeratotic, erythematous-to-violaceous, lichenified plaques with a rim of dusky erythema on the dorsal aspects of the feet and extending to the toes. Based on morphology and histopathologic features, NAE can be difficult to distinguish from certain groups of necrolytic erythemas, which include necrolytic migratory erythema, acrodermatitis enteropathica, biotin deficiency, niacin deficiency, and essential fatty acid deficiencies. The condition is particularly important for clinicians to diagnose because the majority of the patients present to dermatologists without a known history of HCV infection. Thus, NAE can serve as a cutaneous marker for underlying HCV infection. Resolution of NAE can be achieved by treatment of the underlying HCV infection and the use of oral zinc therapy.