Topical Minocycline Versus Oral Doxycycline for Moderate Acne Vulgaris

Abstract

Introduction: Oral tetracyclines are standard for moderate acne but cause gastrointestinal and antimicrobial resistance concerns. Topical minocycline foam 4% may offer comparable efficacy with systemic safety. Methods: Systematic review of 3 RCTs (n=1,412) comparing topical minocycline foam 4% once daily versus oral doxycycline 100 mg/day + topical vehicle, over 12 weeks. Inclusion: inflammatory acne (20–50 lesions). Primary outcome: percent reduction in inflammatory lesion count. Secondary: IGA (Investigator Global Assessment) success (0 or 1 with ≥2-grade improvement). Results: Inflammatory lesion reduction was similar (minocycline 54%, doxycycline 51%, p=0.32). IGA success: minocycline 33%, doxycycline 31%. Topical minocycline had fewer GI adverse events (6% vs 24%, p<0.001) and no cases of vulvovaginal candidiasis. Skin dryness occurred in 12% (both groups). Discussion: Topical minocycline delivers antibiotic directly to pilosebaceous units, avoiding systemic absorption (only 1.5% serum levels). Long-term antimicrobial resistance data are lacking. Conclusion: Topical minocycline 4% foam is non-inferior to oral doxycycline for moderate acne with superior tolerability.