Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology, in which development of fibrosis, vascular insufficiency and inflammatory processes are prominent in the skin as well as in other organs. We studied the effect of photochemotherapy with quantitative echography in SSc. Dermal echo intensity and dermal thickness was measured using high-frequency dermal echography before and after therapy. The dermal echo intensity after photochemotherapy (33.51+/-9.34) significantly increased than that before therapy (21.23+/-6.00) (P < 0.01), while dermal thickness (1.20+/-0.20) significantly decreased than that before therapy (1.38+/-0.18) (P < 0.05). Photochemotherapy was more likely to improve dermal edema, not fibrosis, because echo intensity after treatment was significantly elevated with that before treatment in patients with edema. Quantitative echographic analysis was concluded to be a reliable method in evaluating the change of skin edema in SSc.