An Undetected Case of Tinea Capitis in an Elderly Woman Affected by Dermatomyositis: How Trichoscopy Can Guide to the Right Diagnosis.

Dermatomyositis (DM) is an autoimmune disease that primarily affects the skin and muscles, but may also have a systemic involvement. The frequency of scalp involvement in DM varies from 28 to 82% and is often encountered as part of a DM flare. However, it frequently presents as a treatment-resistant disease, and patients reporting no improvement with conventional therapies require further investigation. We report a case of tinea capitis (TC) in a 79-year-old woman affected by DM with scalp involvement which did not respond to conventional therapies. Thanks to trichoscopy we could detect "comma hairs," "zigzag hairs," and "pigtail hairs" at scalp examination, made the right diagnosis of TC, and instituted the best treatment without delay.