Comparison of five antimicrobial regimens for treatment of mild to moderate inflammatory facial acne vulgaris in the community: randomised controlled trial

We investigated the efficacy and cost-effectiveness of five antimicrobial regimens for mild to moderate facial acne and whether propionibacterial antibiotic resistance affects treatment response. In this randomised, observer-masked trial, 649 community participants were allocated one of five antibacterial regimens. Primary outcomes were patients' self-assessed improvement and reduction in inflamed lesions at 18 weeks. Analyses were by intention to treat. Moderate or greater improvement at 18 weeks was reported in 72 (55%) of 131 participants assigned oral oxytetracycline plus topical placebo, 70 (54%) of 130 assigned oral minocycline plus topical placebo, 78 (60%) of 130 assigned topical benzoyl peroxide plus oral placebo, 84 (66%) of 127 assigned topical erythromycin and benzoyl peroxide in a combined formulation plus oral placebo, and 82 (63%) of 131 assigned topical erythromycin and benzoyl peroxide separately plus oral placebo. Most improvement occurred in the first 6 weeks. Treatment differences for the proportion of people with at least moderate improvement were: minocycline versus oxytetracycline –1·2% (unadjusted 95% CI –13·3 to 10·9); combined erythromycin and benzoyl peroxide versus oxytetracycline 11·1% (–0·7 to 22·9) and versus minocycline 12·3% (0·4 to 24·2); erythromycin and benzoyl peroxide separately versus combined formulation –3·5% (–15·2 to 8·2); benzoyl peroxide versus oxytetracycline 5·0% (–7·0 to 17·0), versus minocycline 6·2% (–5·8 to 18·2), and versus combined formulation –6·1% (–17·9 to 5·7). Benzoyl peroxide was the most cost-effective treatment. Efficacy of both tetracyclines was reduced by pre-existing tetracycline resistance. Topical benzoyl peroxide and benzoyl peroxide/erythromycin combinations are similar in efficacy to oral oxytetracycline and minocycline and are not affected by propionibacterial antibiotic resistance.