Changes of Transepidermal Water Loss (TEWL) in Psoriatic Plaques during D-PUVA Therapy

ABSTRACT

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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). RESULTS: 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. CONCLUSION: In psoriatic plaques, TEWL was decreased according to the improvement. In normal-looking skin, D-PUVA therapy caused only a little effect on TEWL.