In vivo study of skin mechanical properties in patients with systemic sclerosis

Background: Measurements of skin elasticity are more sensitive than the skin severity score and appropriate for evaluation of sclerodermatous skin. Objective: Our purpose was to investigate the mechanical properties of the skin in patients with systemic sclerosis depending on the stage of the disease. Methods: Seventeen patients, 8 with edematous phase and 9 with indurative phase of skin involvement, and 16 healthy subjects were studied. Clinical scoring of skin thickness and measurements of skin elasticity with a noninvasive suction device (Cutometer) were performed over 11 anatomic regions. Results: Edematous phase was characterized by significantly lower immediate distention (U-e) and final distention (U-f), and higher viscoelastic to elastic ratio (U-v/U-e) of the skin compared with indurative phase, except for the forehead (8 mm probe). The changes in skin mechanical parameters for fingers were identical in both phases. Low values of skin distensibility correlated with severe skin thickness or hidebound skin. Results were influenced by body site and by the diameter of measuring probe used. Conclusion: The noninvasive method applied is suitable for objective and quantitative monitoring of skin involvement in patients with systemic sclerosis.