Randomized controlled trial of a water-soluble nail lacquer based on hydroxypropyl-chitosan (HPCH), in the management of nail psoriasis

Abstract

Franca Cantoresi,1 Maurizio Caserini,2 Antonella Bidoli,1 Francesca Maggio,1 Raffaella Marino,1 Claudia Carnevale,1 Paola Sorgi,1 Renata Palmieri21Department of Dermatology, Sapienza University, Rome, Italy; 2Scientific Department, Polichem SA, Lugano, Switzerland Background: Nail psoriasis occurs in up to 50% of patients affected by psoriasis, with a significant impact on quality of life that leads to a real clinical need for new therapeutic options. Aim: To confirm whether the strengthening and hardening properties of the hydroxypropyl-chitosan (HPCH) nail lacquer could improve the structure of the nail plates on psoriatic nails. Materials and methods: A randomized, double-blind, placebo controlled, parallel-group trial was carried out to evaluate the efficacy and tolerability of a hydrosoluble nail lacquer containing HPCH, Equisetum arvense, and methylsulfonylmethane on nail psoriasis. The test product or a placebo was applied once daily for 24 weeks to all fingernails. Efficacy assessments were performed on the target fingernail by means of the modified Nail Psoriasis Severity Index score. A cut-off score of 4 was considered to define the clinical cure rate (ie, Cure ≤4, Failure >4). Results: After 24 weeks, the clinical cure rate showed the statistically significant superiority of the HPCH nail lacquer compared to placebo in both the intention-to-treat (Fisher's exact test, P=0.0445) and the per protocol population (Fisher's exact test, P=0.0437). This superiority was already present after 16 weeks of treatment. Moreover, the analysis of the modified Nail Psoriasis Severity Index-50 showed a statistically significant clinical improvement after 12 weeks of treatment in comparison to the results obtained after 8 weeks (Fisher's exact test, P<0.05). Conclusion: The trial showed that HPCH nail lacquer could be a new, valid, effective, and safe option for decreasing the signs of nail dystrophy in psoriatic patients. Keywords: nail psoriasis, psoriatic onychodystrophy