Assessment of nail fold capillary changes by hand-held dermoscopy in adult dermatomyositis: A single-centre prospective study

Background Hand-held dermoscopy is a valuable tool for dermatologists, but it has been rarely used to assess the nail fold capillary (NFC) in patients with dermatomyositis (DM).Methods Patients were collected from the Department of Dermatology and Venereology from July 2020 to July 2021, and the follow-up was conducted until January 2022. Demographic features, disease activity and NFC changes were analysed using a hand-held dermoscopy.Results The most common NFC finding in our study was bushy capillary (87.0%). There was no significant improvement in scleroderma-dermatomyositis (SD)-like nail fold changes or enlarged capillaries from baseline to 12 weeks of treatment (p > 0.05) or from 12 weeks to 24 weeks of treatment (p > 0.05), but there was a significant improvement from baseline to 24 weeks of treatment (p < 0.05). The avascular area did not improve from baseline to 12 weeks of follow-up, but the changes were significant from 12 weeks to 24 weeks of treatment (p < 0.05) and baseline to 24 weeks of treatment (p < 0.05). Periungual erythema improved significantly from baseline to 12 weeks of treatment (p < 0.05) and baseline to 24 weeks of treatment (p < 0.05), but it did not improve significantly from 12 weeks to 24 weeks of treatment (p > 0.05). There was no significant difference in disease activity between patients with or without specific NFC changes. However, some NFC features improved as disease activity decreased.Conclusion Dermoscopy of NFC is a cost-effective option for the preliminary diagnosis of DM. Further, long-term follow-up is necessary to study the relationship between disease activity and NFC changes.