Efficacy of combined fractional carbon dioxide laser and topical tazarotene in nail psoriasis treatment: A randomized intrapatient left‐to‐right study

Abstract Background Treatment of nail psoriasis is disappointing; due to poor penetrability of topical therapies and variable efficacy of systemic therapies. Fractional carbon dioxide laser (FCL) may enhance penetration of topical therapy for nail psoriasis. Objective To evaluate the efficacy and safety of FCL plus topical tazarotene versus tazarotene monotherapy in the treatment of nail psoriasis. Methods Twenty‐seven patients with bilateral fingernail psoriasis randomly received 3 sessions of FCL at four‐week interval plus once‐daily tazarotene 0.1% gel for one hand, and once‐daily tazarotene 0.1% gel only for 3 months on the other hand. The primary outcome was modified Nail Psoriasis Severity Index (mNAPSI) at 3 and 6 months compared to baseline, and the secondary outcomes included dermoscopic examination and patient global assessment. Adverse events were reported. Results The total, nail matrix, and nail bed mNAPSI scores were significantly improved at 3 and 6 months by both regimens, but they decreased more after FCL/tazarotene combination ( p = 0.001, p = 0.023, and p = 0.001, respectively). Combination therapy showed faster improvement of nail matrix signs and greater efficacy for nail bed signs. The dermoscopic features of the nail plate were the most responsive after both treatments. The combined therapy was more effective in improving the dermoscopic nail bed features. Patient's global assessment scores were significantly higher after the combined therapy. Both treatments were well tolerated. Conclusion Fractional CO 2 laser is an effective and well‐tolerated treatment for nail psoriasis; it improves the outcomes of topical tazarotene especially in nail bed lesions.