Bacterial resistance became a true clinical concern for dermatologists in the 1980s, when the first reports emerged of the resistance of Propionibacterium acnes to oral antibiotics. Subsequent studies have documented acne treatment failure associated with resistance to topical antibiotics. Beyond dermatology practice, antibiotic resistance has now become recognized as a worldwide health concern. In contrast to antibiotics commonly used in the treatment of acne, benzoyl peroxide (BP)'s mechanism of action is different. Benzoyl peroxide is a bactericidal agent. Combining BP with a topical antibiotic in a stable formulation has been proven in clinical trials to reduce total P acnes count by 99.7% after 1 week of therapy, eliminating both susceptible and resistant strains of P acnes. However, we have recently noticed BP's benefits as monotherapy in the treatment of acne. Benzoyl peroxide works rapidly on P acnes without causing antibiotic resistance. Hence, we may have to reconsider the role of topical antibiotics such as clindamycin in the treatment paradigm of acne vulgaris.J Drugs Dermatol. 2013;12(suppl 6):s73-s76.

INTRODUCTION

Theoretical concern about the development of antibiotic resistance emerged almost immediately upon the discovery of penicillin. In fact, Alexander Fleming reportedly said of his discovery, “The bacteria will not take this sitting down.” Just as Fleming and others predicted, bacterial resistance became a true clinical concern for dermatologists in the 1980s, when the first reports emerged of the resistance of Propionibacterium acnes to oral antibiotics.1 Subsequent studies have documented acne treatment failure associated with resistance to topical antibiotics.2

Beyond dermatology practice, antibiotic resistance has now become recognized as a worldwide health concern. The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) has emerged as perhaps the most notable sign of the consequences of resistance and is probably the most widely recognized resistance concern in the general public. As public health officials, health care professionals, and even international governmental organizations continue to suggest strategies to combat resistance, as dermatology providers we may have to be more conscious of our use of antibiotics, especially for the treatment of acne. One of the well-established acne treatments, benzoyl peroxide (BP), has reemerged as an important tool in treating acne while minimizing resistance. New findings suggest that BP may not only help to reduce antibiotic resistance when used in combination with antibiotics, but may also be sufficient to reduce P acnes when used alone as monotherapy without an antibiotic.

The Problem of Resistance

Initial reports of the resistance of P acnes to oral and topical antibiotics raised alarm in the dermatology community. Importantly P acnes resistance rates have been estimated to be as high as 60% in some patient populations.3 Across the health care field, concern about long-term antibiotic use and subsequent resistance risk has grown alongside the number of reports of community-acquired MRSA skin and soft tissue infections. 4,5 One report suggested that in the 10-year period from 1988 to 1998, rates of MRSA at select dermatology outpatient clinics increased by nearly 10-fold, accounting for 11.9% of all S aureus strains in 1998—up from 1.5% in 1988.4 Concern about MRSA in both the medical and lay communities was amplified by the recent emergence of the multidrug-resistant MRSA USA300 clone in San Francisco and Boston.5

Clinicians have largely associated the greatest risk for resistance with the use of oral antibiotics; however, recent research confirms that resistance to topical antibiotics is prevalent among S aureus isolates.6 Globally, resistance to erythromycin is most common. In North America, 57.8% of resistant S aureus strains were resistant to erythromycin. MRSA is the second most common form of resistance globally as well as in North America, accounting for about one-third of global resistance and for 36.9% of resistance in North America. Clindamycin resistance is the third most common, with rates of 21.5% globally and 22.5% in North America (Table 1).6

Understanding Resistance

Scientists have elucidated the processes by which bacterial resistance emerges. Bacteria are adept at developing and transferring resistance, and they can do so rapidly. The phenomenon of “survival of the fittest” applies to antibiotic therapy and bacterial resistance. Those bacteria that demonstrate resistance to an