564 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (4) Inglis, A. S., and Leaver, I. H., Some effects of peroxide oxidation of wool, Textile Res. J., 37, 995-7 (1967). (5) Zahn, H., Gcrthscn, T., and Kchrcn, M., The application of sulfur-chemical analytical methods to permanent waved hair., J. Soc. Cosmetic Chemists, 14, 529-43 (1963). (6) Moore, S., Spackman, D. H., and Stein, W. H., Chromatography of amino acids on sulfonatcd polystyrene resins Improved system, Anal. Chem., 30, 1185-90 (1958). (7) Robbins, C., Infrared analysis of oxidized kcratins, Textile Res. J. 37, 811-3 (1967). (8) Robbins, C., Scott, G. V., and Barnhurst, J. D., A study of causes of variation in the acid dye combing capacity of human hair, Ibid., 38, 1130-6 (1968).

.L 6•oc. Cosmetic Chemists, 20, 565-575 (Aug. 19, 1969) The Etiology of Acne. I. Composition of Sebum Before and After Puberty CARL B. FELGER, Ph.D.* Presented December $, 1968, New York City Synopsis--An investigation of the changes in sebum composition which take place at the time of puberty, relative to their possible role in comedo development, has been initiated. Samples of human facial wipings (sebum) obtained from pre- and postpuberty subjects have been fractionated on silicic acid and compared to similar lipid from expressed comedos. While no qualitative differences could be detected, certain semiquantitative differences in the relative amounts of saturated and unsaturated fatty acids before and after puberty were uncovered via gas-liquid chromatographic analysis. INTRODUCTION One of the more challenging aspects of acne research has been to understand and define the factors responsible for the initiation of comedo formation. Histological evidence has suggested that comedo formation begins as a hyperkeratotic reaction of the duct of the sebaceous gland (1) which not only precedes but initiates a general keratinization of the entire sebaceous structure. This secondary reaction of the sebaceous gland appears as a general sequela of certain cutaneous insults or injuries (2). Chemical insult or "irritation" has been speculated to mimic the series of events which ultimately leads to the occlusion of the follicular lumen of the sebaceous gland with a keratinacious mass (3, 4). These observations have lead to the speculation that sebum contains a lipid component which is capable of acting as an irritant to the duct of the sebaceous gland, thereby initiating the primary hyperkeratinization. * Gillette Research Institute, Inc., 1413 Research Blvd., Rockville, Md. 20850 565