1. Methods are described for the collection of scalp sebum, and for the determination of the density, viscosity, surface tension, and freezing-point of sebum samples from individual subjects.
2. Data are presented from ten acne patients and seven normal subjects, of whom three previously had acne. No significant difference was demonstrated between the sebum from acne patients and controls. The sebum viscosity increased with fall in temperature, but sebum did not solidify at physiological skin temperatures, and it is concluded that sebum viscosity is unlikely to be important in the pathogenesis of acne.
3. There was no relationship between sebum excretion rate and viscosity in individual subjects and sebum viscosity is unlikely to play a major role in the normal regulation of sebum production.