[External erythromycin therapy of acne]

Area of Science:

• Dermatology
• Microbiology

Context:

• Papulo-pustular acne is a common inflammatory skin condition.
• Acne vulgaris is characterized by papules, pustules, and comedones.
• Propionibacterium acnes and Staphylococcus epidermidis are implicated in acne pathogenesis.

Purpose:

• To evaluate the efficacy of a 2% erythromycin solution as monotherapy for papulo-pustular acne.
• To assess the microbiological impact of topical erythromycin on acne-associated bacteria.
• To determine systemic absorption of erythromycin after prolonged topical application.

Summary:

• Twenty-four patients with papulo-pustular acne received an 8-week course of 2% erythromycin topical solution.
• Significant reduction in pustular lesions was observed, followed by improvement in inflammatory papules.
• Microbiological analysis showed a decrease in Propionibacteria and pathogenic staphylococci.
• No detectable erythromycin serum levels were found post-treatment, indicating minimal systemic absorption.

Impact:

• Topical erythromycin demonstrates efficacy in managing papulo-pustular acne.
• The treatment effectively reduces key bacterial populations involved in acne.
• The safety profile is favorable due to lack of systemic absorption.