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

Abstract 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.