Regional Differences in the Thickness (Cell Layers) of the Human Stratum Corneum: An Ultrastructural Analysis

The importance of the stratum corneum as the rate-limiting barrier to perceutaneous penetration has been well documented in the literature. Data have also been reported which suggest that the barrier function of this zone varies among different regions of the body. However, little attention has been given to regional variation of two morphologic parameters know to affect permeability–thickness and number of cell layers. In the present study, significant regional variation in both the mean thickness and the mean number of cell layers has been documented for four selected , sample regions of the body of a population of six adult volunteers, and for two more homogeneous subgroups separated by sex and age. While the pooled data from the total population and the pooled data from the male and female subgroups are in general agreement. It has been shown that there is also marked individual variation within a region that is characteristic and specific for each individual. The number of cell layers appears to account for the variation in thickness.