Efficacy and tolerability of 1.6% phenol-croton peeling versus topical 5% imiquimod in the treatment of actinic cheilitis: a randomized clinical trial.

Background: Trials evaluating the effectiveness of topical treatments for actinic cheilitis (AC) are scarce. Despite no comparative data, phenol-croton peeling has been reported as effective in treating this condition.

Methods: An open, randomized trial was conducted to compare the effectiveness and tolerability of 1.6% phenol-croton peeling versus topical 5% imiquimod for the treatment of AC. Thirty-six patients with biopsy-proven AC were allocated into two groups (1:1): the 5%-IMI group received 5% topical imiquimod three times a week for 30 days, and the 1.6%-CROTON group underwent one session of 1.6% phenol-croton peeling. The primary outcome was the clearance of AC after 56 days. Secondary outcomes included clinical and histological parameters, adverse effects, and clinical results after 180 days.

Results: Complete clinical clearance of AC at D56 and D180 occurred in 17 (94%) participants from the 1.6%-CROTON group but in none from the 5%-IMI group (p<0.01). Improvement in all clinical parameters was more prominent in the 1.6%-CROTON group (p≤0.01). Complete histologic normalization at D56 occurred in 72% of the 1.6%-CROTON group and only 17% in the 5%-IMI group (p<0.01). Histological parameters such as atypia, solar elastosis, and hyperkeratosis reduced in intensity only in the 1.6%-CROTON group (p<0.05). Adverse effects were most intense on D7 in the 1.6%-CROTON group and persisted until D21 in the 5%-IMI group. The study was prematurely terminated at the interim analysis.

Conclusions: A single session of 1.6% phenol-croton peeling produced clinically and histologically superior results with less downtime compared to imiquimod for treating AC.