Nailfold microscopy in adult-onset dermatomyositis in association with myositis antibodies

Dermatomyositis (DM) is an immune mediated inflammatory disease classically associated with muscular and cutaneous involvement. Existing studies have suggested characteristic nailfold findings may be observed in DM, indicating a potential role for nailfold microscopic examination in the diagnosis of DM. To that end, we performed a systematic review of literature pertaining to nailfold microscopic, capillaroscopic, and dermoscopic findings observed in patients with DM, with a secondary review of the association of nailfold microscopic findings with myositis-specific antibody (MSA) and myositis-associated antibody (MAA) status. Thirty-seven papers, representing 346 patients, met inclusion criteria. The most prevalent nailfold findings were evidence of increased vascular diameter (64.5%, n = 223) and decreased vascularity (57.5%, n = 199). Scleroderma-spectrum pattern and microhemorrhage or hemorrhage were both observed in 156 (45.1%) patients. Fifty-one patients had nailfold capillaroscopic findings reported in direct association with antibody positivity and demonstrated a range of nailfold findings, preliminarily suggesting associations between antibody-status and capillaroscopic findings. The results of our study align with existing data indicating the scleroderma-spectrum pattern and the pattern's composite features are prevalent in patients with DM. Our review further demonstrates a variety of nailfold capillaroscopic findings are found in patients positive for MSAs and MAAs.