THE RATE OF SEBUM EXCRETION IN MAN

Abstract

SUMMARY.— The method introduced by Strauss and Pochi (1961) for measuring the rate of sebum secretion has been critically investigated and a number of sources of error defined. These are choice and preparation of absorbing papers, the technique of sebum collection, weighing, and the ambient humidity. A decrease in the absorbency of the paper during the collection was not found. Modification of the method with careful attention to detail has increased the reproducibility of the results and there is good agreement of the results on both sides of the forehead and in collections made over a 7‐week period. The amount of sebum collected in the first 3‐hr, period was greater than in subsequent 3‐hr, periods but there was a direct linear relationship between the amounts collected in the first 3 hr. and subsequent 3‐hr, periods. The view that the method measures the sebum secretion rate is critically discussed in the light of this observation. It is suggested that the amount of sebum collected may be more directly related to the pool of sebum already secreted. Since the size of this pool is related to the rate of sebum secretion the method provides an indirect measure of this function. Until we know more precisely what we are measuring we prefer to use the descriptive term “rate of sebum excretion”.