Antibiotics, acne, and Staphylococcus aureus colonization

To determine the frequency of Staphylococcus aureus colonization among patients with acne and to compare the susceptibility patterns between the patients who are using antibiotics and those who are not using antibiotics.

Survey (cross-sectional) study of patients treated for acne.

Dermatology outpatient office practice

The study included 83 patients who were undergoing treatment and evaluation for acne.

Measure Colonization of the nose or throat with S aureus.

A total of 36 of the 83 participants (43%) were colonized with S aureus. Two of the 36 patients (6%) had methicillin-resistant S aureus ; 20 (56%) had S aureus solely in their throat; 9 (25%) had S aureus solely in their nose; and 7 (19%) had S aureus in both their nose and their throat. When patients with acne who were antibiotic users were compared with nonusers, the prevalence odds ratio for the colonization of S aureus was 0.16 (95% confidence interval [CI], 0.08-1.37) after 1 to 2 months of exposure and increased to 0.52 (95% CI, 0.12-2.17) after 2 months of exposure (P = .31). Many of the S aureus isolates were resistant to treatment with clindamycin and erythromycin (40% and 44%, respectively), particularly the nasal isolates. Very few showed resistance rates (< 10%) to treatment with tetracycline antibiotics.

Unlike current dogma about the long-term use of antimicrobial agents, the prolonged use of tetracycline antibiotics commonly used to treat acne lowered the prevalence of colonization by S aureus and did not increase resistance to the tetracycline antibiotics.