Comparison of the Efficacy of Intralesional Methotrexate and Triamcinolone in the Treatment of Nail Psoriasis: A Randomized, Investigator-Blind, Controlled Trial

Background: Nail psoriasis is a common and challenging-to-treat manifestation of psoriasis. The efficacy of several medications has been studied in treating nail psoriasis with different results. Aim and Objective: This trial assessed the therapeutic efficacy and safety of intralesional methotrexate injection compared to intralesional triamcinolone injection for nail psoriasis. Patients and Methods: Seventeen patients (69 nails) were recruited in this investigator-blind, randomized, controlled trial, and 13 patients (65 nails) completed the study. The severity of the disease was evaluated by the modified Nail Psoriasis Severity Index (mNAPSI) before starting treatment, after each injection, and 8 weeks after the last injection. Thirty-three nails were randomly treated with methotrexate and 32 nails with triamcinolone. A volume of 0.1 mL of the diluted (5 mg/mL) triamcinolone (0.5 mg) or 0.05 mL of methotrexate (1.25 mg) was injected at each point every 3 weeks for four sessions. (Clinical trial registry: Iranian Registry of Clinical Trials. [ID: IRCT20140212016557N7]). Results: Both interventions significantly reduced the mNAPSI score ( P < 0.001). The percentage of reduction of mNAPSI score was more in the triamcinolone-treated nails at the end of treatment ( P = 0.015), but not significantly different in the 8-week follow-up ( P = 0.906). Deterioration of the mNAPSI score was seen only in the triamcinolone group at the end of 8 weeks after discontinuation of treatment ( P = 0.01). Limitations: A relatively small sample size, lack of prolonged follow-up, and absence of response assessment of the nail matrix and bed separately. Conclusion: Intralesional methotrexate is an effective and safe treatment for nail psoriasis, with similar efficacy to intralesional triamcinolone. Methotrexate showed more persistent efficacy compared to triamcinolone.