Diagnostic usefulness of dermoscopy in differentiating lichen aureus from nummular eczema.

Lichen aureus (LA) is a variant of pigmented purpuric dermatosis that is characterized clinically by rust macules, papules or plaques, mainly on the legs. In some cases, LA can be difficult to be distinguished from nummular eczema (NE) with the naked eye. Dermoscopy can be applied to skin lesions, revealing additional features that can be highly valuable for correct diagnosis. This study was conducted to investigate characteristic dermoscopic findings of LA and to identify distinctive features that can differentiate it from NE. Fourteen LA patients and 14 NE patients diagnosed by skin biopsy were enrolled. Skin lesions were evaluated via polarized dermoscopy. On dermoscopy, "coppery orange diffuse coloration of background", "round to oval red globules", "gray dots", and "networks of brownish to gray interconnected lines" were more commonly seen in LA (100%, 92.9%, 42.9% and 64.3%, respectively) compared with NE. "Scales", "shiny yellow clods" and "irregularly distributed brownish-red globules" were more commonly seen in NE (100%, 85.7% and 57.1%, respectively) compared with LA. Dermoscopy provides valuable information for diagnosis of LA and aids in differentiating it from NE.