Measurement of sebum secretion rates in young children.

Sustainable rates of lipid secretion were measured on the foreheads of 24 children, ages 6-8. The method of measurement involved absorption of skin surface lipid into bentonite clay and subsequent separation and measurement of the various lipid classes by quantitative thin-layer chromatography. In 9 of the children, sebum secretion appeared to be virtually nonexistent, judging by the low amounts of lipid recovered and the low percentages of wax esters and squalene, which are purely sebaceous lipid classes. An effect of age on sebum secretion rates was observed with median rates of wax ester secretion, being 7, 28, and 48 micrograms/10 cm2/3 h for 6-, 7-, and 8-year-olds, respectively. These values are well below those of most young adults. The relation between wax ester secretion rate and skin surface lipid composition on the forehead was investigated and found to conform to the formula: microgram wax esters/10 cm2/3 h = 28 X wax esters/(cholesterol + cholesterol esters), with a correlation coefficient (r) of 0.94.