RE-EVALUATION OF FATTY-ACIDS AS INFLAMMATORY AGENTS IN ACNE

[摘要] The quantities of FA [intrafollicular free fatty acids] present in isolated pilosebaceous ducts and in isolated comedones were analyzed. Using these values, the effect of FA on intracutaneous (i.c.) injection into human skin was investigated. The range of FA in 257 isolated pilosebaceous ducts from skin of the upper back of 10 male subjects was 0.19 to 2.43 .mu.g, with an average of 0.89 .+-. 0.75 .mu.g of FA/duct. The mean FA content in 45 open comedones was 63.6 .+-. 24.8 .mu.g/comedone. Fatty acids for i.c. testing were isolated from human skin surface lipids and from hydrolyzed triglycerides purified from pooled isolated sebaceous glands. Twenty-six subjects received 100 .mu.g of FA i.c. in the upper back. The response to FA injections could not be distinguished from the response to saline control injections. By 24 h no erythema, induration, or any visible marks of inflammation were present in the skin of any of the subjects tested. At the histologic level a mild inflammatory infiltrate consisting predominantly of lymphocytes was slightly more marked in the FA injection site than in the saline control injection site. Increasing the amount of FA injected to 500 .mu.g still produced no visible inflammatory response in human skin. I.c. injections of FA in physiologic concentrations apparently do not produce more than a very mild inflammatory reaction in human skin and the role of Propionibacterium acnes in the pathogenesis of acne may be more complex than merely as a source of intrafollicular lipases.