Bacterial resistance in acne.

Antibiotics play a major role in acne therapy. Physicians base treatment choices on personal perceptions of efficacy, cost-effectiveness or risk-benefit ratios and rarely take bacterial resistance into account. It is well documented that resistant strains of coagulase-negative staphylococci within the resident skin flora increase in both prevalence and population density as duration of therapy increases. Acne patients represent a considerable reservoir of resistant strains of these important nosocomial pathogens which can be transferred to close contacts. Resistance in cutaneous propionibacteria has received scant attention in view of the central role of Propionibacterium acnes in inflammatory acne. Isolates resistant to one or more anti-acne antibiotics (most commonly erythromycin) have been reported in Europe, the USA, Japan and New Zealand. Carriage of resistant strains results in therapeutic failure of some but not all antibiotic regimens. In our region, skin carriage of resistant strains by 60% of acne patients and 1 in 2 of their close contacts suggests that resistant strains are widely disseminated. We are beginning to gain an understanding of those factors which encourage resistance development and can identify those patients most likely to possess resistant propionibacterial floras. Recommendations for the use of antibiotics in acne therapy to help prevent the emergence of resistance in P. acnes include the implementation of antibiotic usage policies and the encouragement of improved prescribing habits.