Combined fractional CO2 laser 10,600 nm with methotrexate 1% gel versus methotrexate 1% gel alone in the treatment of nail psoriasis: a randomized comparative study

Methotrexate injections intralesionally as a treatment for psoriatic nails proved to be effective in large-scale studies as well as individual case reports, but the process is painful and time-consuming. The objective of this study was to compare the efficacy and safety of combined fractional CO2 laser (Fr. CO2) 10,600 nm and methotrexate gel versus methotrexate 1% gel alone in treatment of nail psoriasis. In this intra-patient randomized comparative study, 36 patients were treated for finger nail psoriasis. One hand was randomly selected to be treated with a Fr. CO2 laser at 10,600 nm in monthly sessions in addition to the daily application of methotrexate 1% gel for 4 months (Fr. CO2 group). The other hand was treated with daily application of methotrexate 1% gel alone for the same period (non-laser group). Evaluation was done at the end of 4 months treatment and 3 months after treatment both clinically and dermoscopically. In addition, histopathological evaluation was done 3 months after treatment. At the end of treatment, both hands experienced significant improvement in total nail psoriasis severity index (NAPSI) (P = 0.001,for each hand) with no significant difference between both (p = 0.593). Three months after treatment, the improvement in NAPSI score in Fr. CO2 group was significantly greater than that in non-laser group (p = 0.001). The dermoscopic evaluation showed significant improvement in both hands at the end of treatment and 3 months after treatment. Regarding microscopic examination of nail psoriatic, the mean value of nail plate thickness and subungual thickness significantly decreased, three months after treatment in both groups with significant higher improvement in Fr. CO2 group compared with non-laser group (p = 0.011, 0.000), respectively. Nail plate serous lake, subungual serous lake, parakeratosis and Munro's abscess significantly improved 3 months after treatment. with no significant difference between both sides. Although minimal pain during the session was in 20% and erythema in 37.1% of patients that last less than 24 h were noticed in Fr. CO2 group, patient satisfaction was still higher among patients in this group (p = 0.02). It is concluded that topical methotrexate 1% gel is an effective topical treatment for nail psoriasis. However, Fr. CO2 laser-assisted delivery of methotrexate 1% gel is superior to unassisted methotrexate 1% gel application.