Effects of PUVA and UVB treatments on restoration of epidermal barrier function and vascular response after suction blister injury in human skin in vivo

PUVA and UVB phototherapies are used in the treatment of psoriasis and other inflammatory skin diseases. Ultraviolet radiation causes inflammation and modulates cell kinetics in the skin. PUVA also has an inhibitory effect on skin DNA synthesis. In this study, the effects of PUVA and UVB treatments on epidermal wound healing were examined using the suction blister wound model. The healing of the wound was studied indirectly by measuring water evaporation and blood flow in the wound area. On the fourth day, water evaporation was more abundant in PUVA-treated patients (42±5 g/m 2 h) than in UVB treated (36±4 g/ m 2 h) or control patients (27±3 g/m 2 h) (analysis of variance, the least significant difference test at a level of 0.05). The P value for the difference of means between the PUVA and control groups was 0.014. Blood flow was also more abundant during the fourth (PUVA 162±11 arbitrary units, UVB 122±10, controls 115±15) and sixth (PUVA 108±18, UVB 73±17, controls 57±13) day in PUVA treated patients (analysis of variance, the least significant difference test at a level of 0.05). The results suggest that PUVA treatment decreases the restoration of the epidermal barrier function. The PUVA-treated patients also showed a more intense and prolonged vascular response that may be due to PUVA-related inflammation.