In vivo autoradiography and planimetry of epidermis in psoriatics under PUVA-therapy.

The effects of oral 8-methoxypsoralen-photochemotherapy (PUVA)-therapy) on involved epidermis of nine psoriatics and on normal skin of four control subjects was investigated by means of in vivo autoradiography and planimetry. Under PUVA-therapy there is a significant decrease of 3H-TdR labeled cells per epidermal cross-sectional surface, per length of basal membrane and per length of epidermal surface. There is also a significant decrease of epidermal thickness. In the initial phase of PUVA-therapy the decrease of 3H-TdR labeled cells is the most pronounced. The reduction of epidermal thickness is less than the decrease of 3H-TdR labeled cells.