Dermoscopy and Trichoscopy in Dermatomyositis—A Cross-Sectional Study

Background: (Video)dermoscopy is a non-invasive diagnostic technique that has a well-established role in dermatooncology. In recent years, this method has also been increasingly used in the assessment of inflammatory dermatoses. So far, little is known about the (video)dermoscopic features of dermatomyositis (DM). Methods: Consecutive patients with DM were included in the study and videodermoscopic assessments of the nailfolds, scalp, and active skin lesions were performed. Results: Fifteen patients with DM (10 women and 5 men) were included. Capillaroscopy showed elongated capillaries (90.9%), avascular areas (81.8%), disorganized vessel architecture (81.8%), tortuous capillaries (72.7%), dilated capillaries (72.7%), and hemorrhages (72.7%). The trichoscopic findings included linear branched vessels (80.0%), linear vessels (60.0%), linear curved vessels (53.3%), perifollicular pigmentation (40.0%), perifollicular erythema (33.3%), scaling (20.0%), white (20.0%) or yellow (20%) interfollicular scales, and white (20.0%) or pinkish (13.3%) structureless areas. Polymorphic vessels of an unspecific distribution and white or pink structureless areas were frequently observed under dermoscopy in cutaneous manifestations of DM, including Gottron’s papules and Gottron’s sign. Conclusions: Dermoscopy of the nailfolds (capillaroscopy), scalp (tricoscopy), and active cutaneous lesions may be of value in the preliminary diagnosis of DM.