Evaluation of the Efficacy, Safety, and Treatment-Related Skin Irritation of Adapalene-Benzoyl Peroxide Combination Gel and Adapalene Gel in Acne Patients: A Randomized Comparative Study

Background: While adapalene and benzoyl peroxide have both been demonstrated to be effective for the treatment of acne vulgaris, they can also cause skin irritation, resulting in patient incompliance. In addition, the irritation may be severe when adapalene is co-administered with benzoyl peroxide. Objective: The intention of this study was to evaluate the efficacy and safety of adapalene 0.1%-benzoyl peroxide 2.5% fixed-dose combination gel, and adapalene 0.1% gel monotherapy, for the treatment of mild to moderate acne. Any changes in the skin barrier function were also measured. Methods: A total of 52 patients applied adapalene-benzoyl peroxide gel or adapalene gel once daily. The changes in lesion counts, investigator.s global assessment, patient satisfaction, and adverse events were recorded for 6 weeks. The biophysical profiles of the skin, including transepidermal water loss and redness, were measured for 3 weeks. Results: Both agents were effective for the treatment of acne lesions. Adapalene-benzoyl peroxide showed a faster onset of action than adapalene, especially on inflammatory lesions. However, at week 6, both agents showed a similar effect in reducing lesion counts. While most patients in both groups experienced skin irritation from week 1, this gradually reduced. Likewise, the changes in transepidermal water loss and redness showed peak rates at week 1 and 2, but decreased over time. Conclusion: Adapalene-benzoyl peroxide gel is effective for the treatment of acne with a safety profile comparable to adapalene gel. The skin irritation experienced may be associated with the changes in skin barrier disruption, which lasts for 1.2 weeks.