308nm Excimer Laser for Treatment of Fingernail Psoriasis

Psoriasis is a common skin disease, which affects 2-3% of the population. Up to two third of patients with psoriasis develop nail changes. These visible changes can be painful and disabling and are associated with social stigma. Most topical treatments are only partially effective. Systemic treatments can have serious side effects. Excimer laser is a form of targeted ultraviolet light therapy that has been successfully used to treat isolated psoriatic plaques on difficult to treat areas such as scalp or palms. The purpose of this study is to investigate efficacy of excimer laser for treatment of fingernail psoriasis. Sixteen patients with stable fairly symmetric fingernail psoriasis will be enrolled. After obtaining informed consent, an investigator will evaluate the severity of nail psoriasis in each hand using an objective score, called Modified Nail Psoriasis Severity Index (mNAPSI). In a random fashion, one hand will be treated with excimer laser and the other hand will receive sham treatment. During the treatments, patients will wear protective eyewear that does not permit them to see which hand receives active treatment and which hand receives sham treatment. Patients will be treated twice a week for 8 weeks. At weeks 8, 12, and16 the investigator who is blinded to the treatment assignments will re-evaluate the fingernails using mNAPSI score. Mean change from baseline mNAPSI score at weeks 8, 12, and 16 in hands treated with excimer compared to hands treated with sham will be measured. We will also measure patient's assessment of severity of nail disease and the pain or any adverse events associated with laser treatments. Given the slow growth rate of fingernails, the final evaluations will be performed at week 16. In summary, this is the first controlled study to evaluate efficacy of excimer laser in fingernail psoriasis. If found to be effective, excimer laser could be used as a safe, locally administered treatment for recalcitrant nail psoriasis.