Skin Surface Lipids in Infants

The lipid on the surface of human skin is composed of wax esters and squalene from the sebaceous glands, cholesterol and cholesterol esters arising predominantly from the superficial epidermis, and glycerides plus free fatty acids from both sources. The activity of the sebaceous glands goes th rough a number of phases and is largely dependent on underlying endocrine factors. It is high immediately after birth, low in childhood, rises in advance of puberty, becomes high in adolescence and earl y adult !i fe, declines stead ily with age, perhaps more steepl y in females after the menopause, and becomes low in old age. These changes affect the amount and composition of the skin surface lipid and may be important in relati on to the physiological properties, susceptibility to disorders, and cosmetic attributes of the skin.