Measurement of biological ageing in human epidermis.

Measurements were made of the thickness of the epidermis, the dimensions of keratinocytes and of the surface areas of individual corneocytes in normal human skin from three non-light exposed sites. The numbers of cells in the epidermis and their height decreased with age, whereas the surface area of individual corneocytes tended to increase with increasing age. The changes demonstrated may be responsible for some of the alterations noted clinically in the skin of elderly individuals.