Skin vessel leakage of plasma proteins after PUVA therapy

In eight healthy volunteers the effect of PUVA therapy on skin vessel leakiness was examined (a quadrant on one side of the abdominal skin was shielded during the UVA irradiation). The relative concentration of intravenously injected labeled albumin in suction blister fluid from irradiated skin was only slightly elevated 2 days after PUVA treatment, whereas a significant elevation (P less than 0.01) was observed on non-irradiated skin. No significant changes were observed in the concentrations of four endogenous plasma proteins in serum and blister fluid. It is concluded that PUVA therapy can induce an increased vascular leakage of albumin from the skin vessels due to humoral factors. In exposed--in contrast to non-exposed--skin, the findings are influenced by an interstitial oedema.