Bacterial flora of comedones

Area of Science:

• Dermatology
• Microbiology
• Cutaneous Biology

Background:

• Acne vulgaris is a common skin condition characterized by comedones.
• The microbial flora within comedones is thought to play a role in acne pathogenesis.
• Differences in microbial composition between facial and truncal acne lesions are not well understood.

Purpose of the Study:

• To compare the microbial flora of open comedones from the face and upper back in patients with acne vulgaris.
• To investigate whether the microbial flora of comedones reflects the surrounding follicular flora.

Main Methods:

• Quantitative bacterial analysis of individual open comedones from 38 acne vulgaris patients.
• Samples collected from facial and upper back lesions.
• Comparison of aerobic cocci and anaerobic counts between sites.

Main Results:

• Significant difference in aerobic cocci prevalence: 44.6% of back comedones lacked aerobic cocci vs. 9.6% of facial comedones.
• Decreased staphylococci prevalence on the back correlated with lower levels in normal back follicles.
• Anaerobe counts in back comedones were similar to those in normal back follicles.

Conclusions:

• The bacterial flora of acne comedones appears to be an extension of the resident follicular flora.
• Microbial composition of comedones may not be directly related to the initial process of comedogenesis.
• Site-specific differences in follicular flora may influence lesion characteristics in acne vulgaris.