Background: Even though the traditional therapy for nail psoriasis has been used for decades, no randomized, controlled trial of such treatment has been conducted to date.

Objective: To evaluate the efficacy and safety of intralesional triamcinolone injections compared with 0.05% clobetasol ointment for psoriatic nails.

Materials and methods: Psoriasis patients, each with three fingernails with similar degrees of severity, were randomly recruited for intralesional triamcinolone injection group, 0.05% clobetasol ointment group, and a control group. The target Nail Psoriasis Severity Index (NAPSI) score of each finger was evaluated, any adverse effects were recorded, and photographs were taken.

Results: Forty-eight affected nails were analyzed. At the second month, a significantly greater reduction of the target NAPSI score was observed in the injection group compared to the control group (p = .003). There was a greatest reduction of the score in the following two month-period, which showed significant difference from the topical group (p = .003) and the control group (p = < .001). The score of the injection group, however, subsequently rose at the six-month visit so that there was no longer any statistically-significant difference between the three groups.

Conclusions: In spite of its temporary effect, the intralesional triamcinolone injection is an effective and safe treatment for psoriatic nails.