Treatment of Psoriatic Nails with Topical Cyclosporin: A Prospective, Randomized Placebo-Controlled Study

<i>Background:</i> Nail involvement is a frequent event in the course of psoriasis causing severe distress. While systemic cyclosporin (CsA) represents a well-established therapy of psoriasis, its topical use is limited by the difficult penetration of the molecule through the skin and the nail because of its highly lipophilic nature. <i>Objectives:</i> We carried out a prospective randomized placebo-controlled study in order to analyze the effectiveness and tolerability of topical oil-dissolved 70% CsA solution in nail psoriasis. <i>Methods:</i> Sixteen adult patients with nail psoriasis, divided randomly into two groups of 8 patients (group A and group B), were treated respectively with a 70% maize-oil-dissolved oral CsA solution and maize oil alone. To compare the therapeutic effectiveness, all patients were evaluated, before starting the treatment and after 12 weeks of therapy, by the same dermatologists. The patients were also asked to assess the severity of their nail involvement at baseline and at the end of the treatment. <i>Results:</i> In group A, 3 patients came to a complete resolution of nail lesions and 5 showed a substantial improvement of the overall severity score. In group B, a slight improvement was noted in only 1 patient. All the patients of group A judged positively the results of the therapy, while in group B only 1 patient reported a moderate improvement. <i>Conclusion:</i> Our results show that topical therapy with oral CsA solution is a safe, effective and cosmetically highly acceptable treatment modality for nail psoriasis. The ability of CsA to influence keratinocyte proliferation and T-cell lymphokine release, reducing the cornification of the upper layers of the epidermis, may prevent the typical alterations observed in nail psoriasis.