1989 年 23 巻 1 号 p. 5-8
The purpose of this study was to investigate the incidence of parakeratotic stratum corneum cells on the cheek skin surface from 335 healthy subjects and the changes of them according to their ages. We also studied the quantitative levels of parakeratotic cells in various regions of face. Stratum corneum cells were collected by tape-stripping method and observed with hematoxyrin-eosin stain after formalin fixation.
In our results, parakeratotic cells were observed in 68.4% of the total subjects, 64.4% of them were women and 72.7% of them were men. They were observed at about 80% in second and third decades of women and decreased as the age advanced. On the other hand, they were observed at about 80% after the first decade in men.
Quantity of parakeratotic cells was the highest in upper cheek and followed by the forehead and nose. They were seldom observed below the cheek and chin.
It was suggested that the parakeratotic cells were appeared in the stratum corneum cells in face, because our facial skin is always exposed to many external stimulations such as ultraviolet rays and so on and turn over of epidermis was accelerated. Moreover, we strongly suggested that sebum is one of the factor causing parakeratosis. Because parakeratotic cells were observed more frequently in the region where sebum level was high and most of them were observed around the pore of the hairs.
Appearance of parakeratotic cells on skin surface implied the loss of skin barrier function and was important problem to the beauty and healthinèss of skin.