[PUVA therapy: long-term degenerative effects. II. Study of ultrastructural changes in the skin induced by PUVA therapy].

The authors studied PUVA induced ultrastructural alterations in a group of 7 patients compared with 6 control subjects of same age. Hyperactivity of melanocytes was observed in all patients. Elastic fibers showed vacuolisation age and dose related. There was a reduplication of the basal layer of dermal capillaries and increased pinocytosis of endothelial cells, age and dose related also. The authors conclude that PUVA therapy induced alterations are degenerative; the target is located in deep dermis (capillaries and elastic fibers). No alterations of keratinocytes nor precancerous epithelial dysplasia was found. This confirms that UVA radiation is less aggressive for keratinocytes than UVB.