Abstract The components in human sebum that mediate the formation of comedones in the rabbit ear were evaluated by applying various sebum fractions as well as individual authentic components of sebum. Practically all the major constituents of sebum had some activity. The activities of the triglycerides and waxes were respectively moderate and weak. Among the saturated fatty acids activity began at C10, reached a peak at C12 and C14, lessened at C16 and C18, and was absent at C20. Monounsaturation increased comedogenicity but high unsaturation had the opposite effect. Irritancy and comedogenicity were shown to be unrelated properties. The lower fatty acids C3 and C5 were highly irritating and noncomedogenic while C16 and C18 were comedogenic and non-irritating. The sebum of various animals had borderline comedogenicity because of the absence of triglycerides and fatty acids. References 1. Kligman AM, Katz AG: Pathogenesis of acne vulgaris: I. Comedogenic properties of human sebum in external ear canal of the rabbit . Arch Derm 98:53-57, 1968.Crossref 2. Lorincz DL, Krizek H, Brown S: Follicular hyperkeratinization induced in the rabbit ear by human skin surface lipids . Read before the 13th International Congress of Dermatology, Germany, 1967 . 3. Haahti E: Major lipid constituents of human skin surface, with special reference to gas-chromatographic methods . Scand J Clin Lab Invest 13( (suppl 59) ):1-87, 1961.Crossref 4. Nicolaides N, Rothman S: Studies in the chemical composition of human hair fat: II. The overall composition with regard to age, sex and race . J Invest Derm 21:9-14, 1953.Crossref 5. Nicolaides NC, Rice GR: The skin surface lipids of man compared with those of 18 species of animals . J Invest Derm 51:83-89, 1968.Crossref 6. Ramasatry P, Downing DT, Pochi PI, et al: Changes in human skin surface lipid composition from the neonatal period to adolescence . J Invest Derm 52:383-388, 1969. 7. Downing DT, Strauss JS, Pochi PE: Variability in the chemical composition of human skin surface lipids . J Invest Derm 53:322-327, 1969.Crossref 8. Strauss JS, Kligman AM: The pathologic dynamics of acne vulgaris . Arch Derm 82:779-790, 1960.Crossref 9. Strauss JS, Pochi PE: Intracutaneous injection of sebum and comedones . Arch Derm 92:443-456, 1965.Crossref 10. Kellum RE: Acne vulgaris: Studies in pathogenesis, relative irritancy of free fatty acids from C2 to C16 . Arch Derm 97:722-726, 1968.Crossref 11. Kligman AM, Fulton JE, Plewig G: Topical vitamin A acid in acne vulgaris . Arch Derm 99:469-476, 1969.Crossref 12. James AT, Wheatley VR: Studies of sebum: The determination of the component fatty acids of human forearm sebum . Biochem J 63:269-273, 1956. 13. Nicolaides N: Skin lipids: IV. Biochemistry and function . J Amer Oil Chem Soc 42:40-43, 1965. 14. Shalita AR, Wheatley VR: Inhibition of pancreatic lipase by tetracycline . J Invest Derm 52:384-386, 1969. 15. Strauss JS, Pochi PE: Effect of orally demonstrated antibacterial agents on titratable acidity of human sebum . J Invest Derm 47:577-581, 1966.Crossref 16. Goltz RW, Kjartansson S: The effects of oral tetracycline treatment in the bacterial flora of the skin in acne vulgaris . Arch Derm 93:92-100, 1966.Crossref 17. Marples RR, Downing D, Kligman AM: Control of free fatty acids in human surface lipids by Corynebacterium acnes, to be published.
Archives of Dermatology – American Medical Association
Published: Sep 1, 1970