Fractional Carbon Dioxide Laser versus Trichloroacetic Acid 20% Peel in the Treatment of Acanthosis Nigricans: A Split Neck Comparative Study.

BACKGROUND: Acanthosis nigricans (AC) is a common chronic skin disorder clinically presenting as velvety, hyperpigmented lesions that can affect any part of the body, including the face. OBJECTIVE: We sought to evaluate and compare the efficacy and safety of fractional CO₂ laser and TCA 20% peel in the treatment of pseudo-acanthosis nigricans.

METHODS: The current study adopted an experimental, comparative split-neck design. It included a total of 20 patients with bilateral pseudo-acanthosis nigricans of the neck. Each patient was subjected to four sessions, spaced three weeks apart, involving fractional CO₂ laser therapy on the right side and TCA 20% application on the left side. The evaluation of cases involved the utilization of the ANASI score and the assessment conducted by two dermatologists blinded to the treatment, both prior to and three months following the treatment.

RESULTS: Regarding Clinical improvement, 20% of the Fractional CO₂ laser side had excellent improvement, and 45 percent had marked improvement. In contrast, the TCA 20% peel side had 2 percent marked improvement, 50 percent moderate improvement, and 40 percent mild improvement. In terms of response to therapy sessions, there was a statistically significant difference between the studied treatment sides ( p <0.001). Regarding ANASI score differences between treated sides before and after treatment, a statistically significant reduction in ANASI score was observed, with a higher percentage of reduction in the Fractional CO₂ laser side compared to the TCA 20% peel side.

LIMITATIONS: The primary limitations are the small sample size and short follow-up period.

CONCLUSION: In the treatment of pseudo-acanthosis nigricans, it appears that fractional CO₂ laser and TCA 20% are promising, effective, and well-tolerated modalities. However, the Fractional CO₂ laser was associated with a better response.