Laser and light therapies for the treatment of nail psoriasis.

Psoriatic involvement of the nail is notoriously refractory to conventional therapy. Nail psoriasis has a high incidence amongst patients with psoriasis. It remains a significant cosmetic problem and thus, has a significant impact on quality of life. More recently, light and laser therapies have emerged as modalities for treatment of nail psoriasis. In this study, the efficacies of light and laser therapies are systematically reviewed. Light therapies involve ultraviolet light (with or without photosensitizers) or intense pulsed light. Alternatively, laser therapy in nail psoriasis is primarily administered using a 595-nm pulsed dye laser. These modalities have demonstrated significant improvement in psoriatic nail lesions, and even complete resolution in some cases. Both laser and light modalities have also been tested in combination with other systemic or topical therapeutics, with variable improvement in efficacy. Both laser and light therapies are generally well tolerated. Side-effects of light therapies include hyperpigmentation, itching and erythema; whereas, side-effects of laser therapy are more frequent and include pain, purpura/petechiae and hyperpigmentation. Patterns of response to therapy were also seen based on presenting characteristics of the nail lesions: subungual hyperkeratosis and onycholysis appeared to be the most responsive to therapy, while nail pitting was the most resistant. Light or laser therapies have the potential to be an efficient and cost-effective in-office based treatment for nail psoriasis. However, more large-scale clinical trials are needed to assess their efficacy, particularly in combination with other therapeutic modalities.