INTRODUCTION
Benzoyl peroxide (BPO) has a long history of use in the management of acne vulgaris (AV) and has been formulated in a variety of concentrations and vehicles including creams, gels, and cleansers.1,2 Topical BPO products are available as both prescription and over-the-counter medications.3 Because the use of BPO has historically been limited by skin irritation (dryness, peeling, erythema, stinging, or burning), Mills et al compared three concentrations of BPO (2.5%, 5%, and 10%) to assess differences in efficacy and tolerability.2 The results using vehicle formulations designated in the study showed that tolerability was best at the 2.5% concentration, while differences in efficacy were marginal between the different concentrations.2 Since then, newer formulation methods such as micronization and microencapsulation have led to leave on BPO products with improved tolerability and bioavailability. Experimenting with these techniques and others, including changing vehicles to maximize solubility, in turn, facilitated the combination of BPO with other topical medications.3
BPO is a potent antibacterial agent, acting through the oxidation of bacterial proteins.4 BPO degrades rapidly to benzoic acid after penetrating the stratum corneum and releasing reactive oxygen species which damage bacterial cell walls.3 This antimicrobial mechanism, which is not associated with the emergence of antibiotic-resistant bacterial strains has led to recommendations for the use of BPO as an integral component of AV management in all patients with few exceptions.5,6 The exceptions include patients highly intolerant of BPO use due to marked irritation, those with true skin allergy to BPO (rare), and those undergoing treatment with oral isotretinoin. To date, no bacterial resistance to BPO has been reported, and adding BPO to AV treatment regimens containing antibiotics reduces the development of resistance in the skin exposed to BPO.7 Leyden et al showed in studies using either a leave-on or 6% cleansing formulation that BPO almost completely suppressed Cutibacterium acnes (97% reduction), including antibiotic-resistant strains.8,9
BPO is a potent antibacterial agent, acting through the oxidation of bacterial proteins.4 BPO degrades rapidly to benzoic acid after penetrating the stratum corneum and releasing reactive oxygen species which damage bacterial cell walls.3 This antimicrobial mechanism, which is not associated with the emergence of antibiotic-resistant bacterial strains has led to recommendations for the use of BPO as an integral component of AV management in all patients with few exceptions.5,6 The exceptions include patients highly intolerant of BPO use due to marked irritation, those with true skin allergy to BPO (rare), and those undergoing treatment with oral isotretinoin. To date, no bacterial resistance to BPO has been reported, and adding BPO to AV treatment regimens containing antibiotics reduces the development of resistance in the skin exposed to BPO.7 Leyden et al showed in studies using either a leave-on or 6% cleansing formulation that BPO almost completely suppressed Cutibacterium acnes (97% reduction), including antibiotic-resistant strains.8,9
