Quantification of cutaneous sclerosis with a skin elasticity meter in patients with generalized scleroderma

Background: The skin score, a subjective assessment of skin elasticity, is widely used in patients with systemic sclerosis. Although this scoring method is regarded as a validated and accepted tool, the interobserver and intraobserver reproducibility is relatively poor. Objective: Our purpose was to investigate whether the recently developed SEM 474 cutometer, which exerts a controlled vacuum force to the skin, can measure skin elasticity more objectively than the skin score. Methods: Skin elasticity was measured in 74 different body areas in patients with systemic sclerosis and compared with the skin score obtained from the same areas. Results: The cutometer produced quantitative and reproducible data. A large-diameter (8 mm) measuring probe was superior to a small probe. The interobserver intraclass correlation coefficient (ICC) was 0.92; the intraobserver ICC was 0.94. A linear correlation was found with the clinical skin score; the Spearman rank correlation test was 0.69. Conclusion: The correlation with the skin score was reasonable, despite the observation that regional differences in skin elasticity were detected by the cutometer but not by the human observer, who automatically compensates for these factors and integrates them into the skin score. The high interobserver and intraobserver ICC makes the cutometer more suitable for quantifying changes in skin thickness than the subjective skin score.