Psoriatic lesions have reduced water-holding capacity and show increased transepidermal water loss (TEWL). The effect of D-PUVA therapy, which combines topical calcipotriol and PUVA therapy, on epidermal barrier function has not yet been evaluated.

The purpose of this study was to verify the change of TEWL in lesional and normal skin according to D-PUVA therapy in psoriasis patients.

TEWL was measured consecutively by TEWAMETER TM210®, in 13 psoriasis patients who received D-PUVA therapy. Clinical grading was done according to psoriasis severity index (PSI).

TEWL of psoriatic lesion decreased as D-PUVA continued. TEWL of normal-looking skin gradually increased, although the increase was trivial. Clinical grading of scale and in-filtration followed the pattern of PSI in the decrease of TEWL, while that of erythema did not.

In psoriatic plaques, TEWL was decreased according to the improvement. In normal-looking skin, D-PUVA therapy caused only a little effect on TEWL.