Nailfold capillaroscopy findings in cutaneous lupus erythematosus patients with or without digital lesions and comparison with dermatomyositis patients: A prospective study

Background Differential diagnosis between cutaneous lupus erythematosus (CLE) and dermatomyositis (DM) may be challenging if digital lesions occur. Objectives To compare nailfold capillaroscopy (NFC) findings in CLE patients with or without digital involvement, and to compare capillaroscopic findings between CLE patients with digital lesions and DM patients. Methods Prospective monocentric study including CLE and DM patients. NFC was performed and standardized items were recorded. Results Fifty-one CLE patients and 10 DM patients with digital lesions were included. A scleroderma pattern was found in 6 patients (12%): in 5 out of 17 patients with digital lesions, compared with only 1 out of 34 patients without digital lesions (p = 0.01). In multivariate analysis, CLE digital lesions and digital ulcerations were statistically associated with scleroderma pattern. CLE digital lesions were significantly associated with architectural disorganization (p = 0.0003) and capillary rarefaction (p = 0.0038). A scleroderma pattern was significantly more frequent in DM patients (80%) than in CLE patients with digital lesions (30%, p = 0.018). Capillaroscopic findings were not significantly different between CLE patients with digital lesions and DM patients. Conclusion Although scleroderma pattern is more frequent in DM patients than in CLE patients with digital lesions, NFC cannot formally distinguish CLE from DM.