Dr. Freiman discusses the issue of antibiotic resistance in acne therapy in The Chronicle of Skin and Allergy. The use of antibiotic treatments to manage acne is contributing to the global dilemma of antibiotic resistance, so therapeutic strategies need to address this development, according to Dr. Anatoli Freiman, the medical director of the Toronto Dermatology Centre. “Antibiotic resistance is an international concern,” said Dr. Freiman, speaking in Toronto at Primary Care Today 2014 regarding the threat of antibiotic resistance linked to acne treatment. He pointed to recent news about a World Health Organization report, which warned of the threat of antibiotic resistant bacteria. Acne is a chronic condition that can require maintenance therapy, said Dr. Freiman, noting that there is evidence suggesting it can persist into adult years in about half of affected individuals. Choices of topical anti-acne treatments include topical retinoids, topical antibiotics, and benzoyl peroxide, with one of the objectives of treatment being the suppression of Propionibacterium acnes (P. acnes), according to Dr. Freiman. Treatment should also target inflammation and abnormal desquamation, he added. Antibiotics, both oral and topical, have been mainstays of acne management for more than half a century, but clinicians are being encouraged to prescribe antibiotics sparingly because of the threat of antimicrobial resistance, explained Dr. Freiman.
The last 30 years has seen a disturbing rise in resistance to antibiotics that have been commonly prescribed to treat acne. That figure was 20% in 1978 rising to 73% in 1995. Investigators have found that resistance to some antibiotics is greater than with others: erythromycin and clindamycin resistance is more prevalent than resistance to tetracycline, for example. In as short a period as two months, strains resistant to P. acnes have been observed to emerge after just eight weeks of topical antibiotic monotherapy. Using benzoyl peroxide can be an effective strategy to address antibiotic-resistant P. acnes. In one study, the use of benzoyl peroxide cleanser 6% resulted in a decrease of total P. acnes count and decrease in counts of strains resistant to antibiotics such erythromycin, tetracyclines, and clindamycin. “Benzoyl peroxide does not trigger resistance,” said Dr. Freiman. “It’s anti-inflammatory, and it’s great to use to treat acne.” P. acnes is not regarded as a pathogen in most human diseases, so perhaps it may not be apparent that antibiotic resistance in acne could be part of any larger health concern. Topical and oral antibiotics that are options for acne therapy, however, can result in resistant strains of coagulase-negative staphylococcus, which can then transfer resistance to Staphylococcus aureus. Indeed, an increase in resistant S. aureus has been identified in acne patients treated with antibiotics.
Moreover, a three-fold rise in the prevalence of Group A streptococci in the oropharynx of acne patients treated with antibiotic therapy has been observed. Dr. Freiman noted that the growing problem of antibiotic resistance has been coupled with decreased clinical responses. A systematic review of 50 clinical trials found declining efficacy of topical erythromycin administered in patients with acne. Extended use of antibiotics offers the opportunity for horizontal gene transfer, according to Dr. Freiman. “There is a concern about horizontal gene transfer,” he said, explaining horizontal gene transfer occurs between organisms such that resistance can be passed to unrelated bacteria. Strategies to limit resistance of P. acnes include shortening the course of antibiotic therapy and avoiding inappropriate use of antibiotics, said Dr. Freiman. First-line therapy should combine a topical retinoid with an antimicrobial agent, either oral or topical, said Dr. Freiman. When an antibiotic is prescribed, an agent containing benzoyl peroxide should be prescribed in combination or a benzoyl peroxide product can be used as a wash. Maintenance therapy can consist of topical retinoids, with benzoyl peroxide added as needed.