Dermoscopy for the Differentiation of Subacute Cutaneous Lupus Erythematosus from Other Erythematous Desquamative Dermatoses-Psoriasis, Nummular Eczema, Mycosis Fungoides and Pityriasis Rosea.

Subacute cutaneous lupus erythematosus (SCLE) is a condition that might pose a diagnostic challenge. The aim of this study was to assess the usefulness of videodermoscopy in the differentiation of SCLE from other erythematous-desquamative dermatoses. Consecutive patients with SCLE ( n = 27), psoriasis ( n = 36), nummular eczema ( n = 30), mycosis fungoides ( n = 26), and pityriasis rosea ( n = 20) referred to our Department of Dermatology were recruited for this study. A representative lesion was visualized using a Canfield D200EVO Videodermatoscope (Canfield Scientific GmbH, Bielefeld, Germany) and evaluated for the following parameters: vessels (morphology and distribution), scales (color and distribution), follicular findings, colors and morphologies, and presence of specific clues. SCLE was predominantly characterized by a polymorphous vascular pattern (92.6%) of unspecific distribution (92.6%) over a pink-red background (74.1%). Gray-brown dots were present in 10 (37.0%) cases, and pigmentation was noted in 15 (55.6%) patients, including peripheral pigmentation in 7 (25.9%) patients. Videodermoscopic evaluation showed significant differences between SCLE and psoriasis, which was characterized by regularly distributed dotted vessels. Although some common dermoscopic features with MF were noted, the presence of yellow structureless areas and red dots/globules favored the diagnosis of MF. In conclusion, a polymorphic vascular pattern, especially in association with gray-brown dots and/or peripheral pigmentation, is a valuable clue for the differentiation of SCLE from other erythematous-desquamative dermatoses.