Nail involvement in connective tissue diseases: an epidemiological, clinical, and dermoscopic study

The assessment of nail changes in connective tissue diseases (CTD) has been rarely explored in previous studies. The use of dermoscopy to study vascular changes in nailfolds is an interesting diagnostic technique. The aim of the study was to describe the epidemiological, clinical, and dermoscopic features of nail lesions in CTD.

A prospective study was performed at the Dermatology Department of Habib Thameur Hospital (Tunis, Tunisia) in collaboration with the Internal Medicine Department over a period of 15 months, from July 2020 to September 2021, including patients diagnosed with systemic sclerosis (SS), systemic lupus erythematosus (SLE) and dermatomyositis (DM).

Our study included 48 patients. Nail involvement was found in 44 cases. Dermoscopic nailfold abnormalities were identified in 37 cases. The most common clinical features were ragged cuticle, nailfold erythema, and onycholysis. Additionally, splinter hemorrhage, longitudinal ridging, lunula abnormalities, melanonychia, trachyonychia, leukonychia, increase in transverse curvature, parrot beak nail, half and half nails, and onychorrhexis were described. Nailfold dermoscopy showed a normal pattern in 10 cases, a nonspecific pattern in nine cases (SLE), and a scleroderma pattern in 29 cases (SS and DM). The scleroderma pattern was further categorized into an early pattern (6), an active pattern (14), and a late pattern (9). Normal pattern was observed solely in patients in remission. The late scleroderma pattern was associated with disease duration and systemic involvement. In SLE, disease activity correlated with onycholysis, nailfold erythema, and pathologic pattern in dermoscopy. However, patients with DM displayed a positive correlation between pulmonary involvement and scleroderma pattern.

Nail involvement in CTD includes a diverse range of abnormalities. Despite being nonspecific, it can provide crucial clues for establishing a diagnosis. Nailfold dermoscopy serves as a mirror for microangiopathy, enabling the detection of changes at an initial stage, and thus, it becomes a diagnostic and prognostic tool.