Dermatomyositis: Dermoscopic features and a short review

Dermoscopy has demonstrated utility in several connective tissue diseases. However, in dermatomyositis, it has been poorly studied for both cutaneous and nailfold involvement.

We report the cutaneous and nailfold dermoscopic features in 11 patients with dermatomyositis and compare them with previously published data.

Key cutaneous findings included linear vessels with a uniform distribution, white scales observed in all 11 patients, structureless white areas in 9 patients, brown globules in 9 patients, and mottled brown pigmentation in 8 patients. Nailfold dermoscopy revealed dilated capillaries and avascular areas in all patients, architectural disorganization in 10 patients, tortuous vessels in 8 patients, hemorrhages in 7 patients, and megacapillaries in 2 patients. Few studies have described dermoscopic features in dermatomyositis, some of them being isolated case reports with incomplete and heterogeneous clinical data. The largest published series included 29 patients and described polymorphic cutaneous vascular patterns, predominantly sparse white scales, as well as nailfold megacapillaries and dilated capillaries, without reporting follicular structures, shapes, or colors.

Larger studies are needed to more precisely identify the distinctive dermoscopic signs of dermatomyositis and to evaluate the potential of dermoscopy as a prognostic tool for disease activity and progression.