Topical cyclosporine versus emulsion vehicle for the treatment of brittle nails: a randomized controlled pilot study.

Background: Limited options are available for the treatment of brittle nail syndrome. Objective: To assess the efficacy and safety of topical cyclosporine emulsion (CsAE) versus emulsion (vehicle) alone in the treatment of brittle nail syndrome. Results: Twenty-four patients were randomized to topical CsAE emulsion or emulsion (vehicle) for 24 weeks. Four fingernails of each patient were included; the 2 most severe brittle nails and the second most normal nail were treated with the same medication. The fourth nail, the most normal nail, remained untreated and was used to assess nail growth. The prespecified primary endpoint was change from baseline in Physician Global Assessment (PGA) score (0 to 5 scale) at each follow-up visit. Safety evaluations were conducted at each visit. Results: In the intent-to-treat population (n=12 for each treatment arm), the PGA score for treated nails improved from baseline (CsAE, 0.7 to 1.4; emulsion, 0.7 to 1.5; P<0.05 for each), with no significant between-group differences. Untreated nails did not improve in overall appearance (0.0 to 0.3 grade; P>0.05). Statistically and clinically significant improvement from baseline was reported for nail length/appearance in both CsAE and vehicle groups. Limitations: Sample size was relatively small. The difference in PGA between treated and untreated nails was not analyzed. Baseline disease severity may have been too mild, limiting detection of efficacy. Conclusions: Both CsAE and emulsion vehicle applied topically appeared to improve signs and symptoms of brittle nail syndrome and were well tolerated. These findings warrant corroboration in a larger population and inclusion of comparison with an inactive control and a higher concentration of CsAE, the former which may help in distinguishing the efficacy of vehicle emulsion from CsAE.