Clinical Comparison of Topical 2.5% Benzoyl Peroxide plus 5% Niacinamide to 2.5% Benzoyl Peroxide Alone in the Treatment of Mild to Moderate Facial Acne Vulgaris.

The combination of benzoyl peroxide and a new topical therapy, such as topical niacinamide, reduces facial sebum production and also has a skin-lightening effect. This combined treatment might lead to improved efficacy in the treatment of facial acne vulgaris while also promoting the resolution of postacne erythema and postinflammatory hyperpigmentation.The primary objective was to evaluate and compare the clinical efficacy of topical 2.5% benzoyl peroxide plus 5% niacinamide and 2.5% benzoyl peroxide with cream base for mild to moderate facial acne vulgaris. Secondary objectives were to evaluate and compare clinical efficacy regarding postinflammatory hyperpigmentation, postacne erythema, reduction of facial sebum production, and side effects. METHODS: Patients with mild to moderate facial acne vulgaris and aged 18 to 40 years were enrolled. Treatment was randomly assigned to the left or right side of the face for 12 weeks. Both inflammatory and noninflammatory acne lesions were counted by a physician, and the postinflammatory hyperpigmentation score and postacne erythema score were calculated using an Antera 3D® camera (Miravex, Dublin, Ireland). Sebum casual level was measured using a Sebumeter® (Courage+Khazaka Electronic, Köln, Germany) every two weeks. Physician improvement score, patient satisfaction index, and side effects were assessed by evaluation forms every two weeks.At Week 12, the niacinamide group (5% niacinamide+2.5% benzoyl peroxide) showed significant reduction in both the acne lesion count and sebum casual levels from baseline (p=0.000 and p=0.001, respectively). The reduction in noninflammatory lesion count in the niacinamide group was better than that in the cream base group (2.5% benzoyl peroxide+cream base), with a statistically significant difference (p=0.004). However, the reduction in inflammatory lesions was not significantly different between the two groups. The sebum casual level in the niacinamide group was reduced faster than that in the cream base group. The postacne erythema score was reduced from baseline in both groups, with no statistically significant difference within or between the two groups. The postinflammatory hyperpigmentation score showed increases in both groups above the baseline, with a statistically significant difference in the cream base group (p=0.000) but no such difference in the niacinamide group (p=0.58). There was no statistically significant difference between the two groups. Furthermore, no statistically significant differences were found between the two groups at every follow-up visit in terms of physician improvement scale, patient satisfaction index, or side effects.The combination of 2.5% benzoyl peroxide and 5% niacinamide is more effective than 2.5% benzoyl peroxide alone for mild to moderate facial acne vulgaris.