The role of sebum and epidermal lipids in the cosmetic properties of skin.

Synopsis Lipids found in the skin are derived both from the keratinized epidermis and from the sebaceous glands. The composition of human sebum and epidermal lipids has only been fully elucidated during the past few years, and the role of these lipids is still being evaluated. This presentation reviews sebaceous gland structure and function composition of human sebum, the effects of aging and hormones on sebum secretion and the role of sebum in acne and in dry skin. In addition, a review of the role of epidermal lipids in the properties of skin includes consideration of the structure and function of the epidermis, the composition of the epidermal lipids, and the function of lipids in epidermal differentia-tion and water barrier properties. Le role du sébum et des lipides de I'épiderme dans les propriétes cosmétiques de la peau.