Microvascular leakage of plasma proteins after short-term PUVA treatment.

The transcapillary escape rate of albumin (TERalb) i.e., the fraction of intravascular albumin, that passes to the extravascular space per unit time is a parameter of the leakage of macromolecules from the total microvasculature. In this study TER alb was measured before and after PUVA treatment to psoriatic patients to study functional alterations in the microvasculature induced by the treatment. Short-term PUVA treatment caused a statistically significant increase in TERalb in 7 out of 8 patients (p less than 0.05). This seems to be a functional equivalent to the morphological changes in the dermal capillary of psoriatic skin and the ultrastructural changes in the dermal vessel walls described after PUVA treatment. It suggests, that the amorphous perivascular masses described in the psoriatic skin after PUsult of increased vascular permeability.