Dermoscopic Features of Nail Psoriasis: Revisited

Nail psoriasis poses a diagnostic challenge in a context of clinical findings that are not evident. We aimed at exploring dermoscopic findings of nail psoriasis and assessing the relationship between these features with disease severity and the risk of arthritis.

We enrolled 35 patients (26 men, 9 women) with severe nail psoriasis (Nail Psoriasis Severity Index [NAPSI] score of more than 50). A complete clinical evaluation, including musculoskeletal assessment and videodermoscopic examination of all nails, was carried out for each patient.

Splinter haemorrhage was the most common finding (94.3%), followed by distal onycholysis (88.6%) and pitting (74.3%). The presence of subungual hyperkeratosis (SUH) and the absence of mottled lunula were associated with disease severity (p < 0.05). Both SUH and nail plate crumbling (NPC) were observed more in patients with arthritis. The presence of a combination of SUH and NPC was associated to a 15-fold increase in the risk of arthritis (%95 confidence intervals: 1.55-145.2, p < 0.05).

This study presents preliminary evidence for the use of dermoscopy as a first step in the diagnosis of nail psoriasis. Dermoscopy is an indispensable tool in the primary evaluation of patients with nail psoriasis, which provides predictive information about the course of the disease.