Abstract
The effect of etretinate, applied systemically, on epidermal Langerhans cells was studied. The numbers and shapes of Langerhans cells were observed on split epidermis, and the percentage of Langerhans cells in whole epidermal cells was determined with a flow cytometrial system. On an epidermal sheet, the number of Langerhans cells changed biphasically, first the number increased, then decreased, and finally it returned to normal. The percentage of Langerhans cells was drastically decreased by etretinate and the low value was maintained during the etretinate treatment. This difference may be due to a decrease in the cell surface marker.
