How much of skin improvement over time in systemic sclerosis is due to normal ageing? A prospective study with shear-wave elastography.

Abstract

Objective To assess changes in skin stiffness in SSc patients using SWE during a five-year follow-up. Methods Skin stiffness [i.e. shear-wave velocity values (SWV) in m/s] was assessed by SWE ultrasound (using virtual touch image quantification) at the 17 sites of the mRSS, in each participant, at baseline and follow-up. mRSS was performed at both time points. Differences between groups were analysed using the related-samples Wilcoxon Signed Rank test and the Mann–Whitney U test. Results We included 21 patients [85.7% females; mean age 56.3 (10.4) years at baseline, 57.1% with limited SSc] and, 15 healthy controls [73.3% females; mean age 53.6 (14.1) years)]. The median follow-up was 4.9 (0.4) years. Skin stiffness decreased significantly at all Rodnan sites (p≤0.001), (except in the fingers), in SSc patients, over time. The same phenomenon occurred in controls, but to a lesser degree, in terms of percentage change. The percentage reduction in skin stiffness varied in the different Rodnan sites and in different phases of the disease. In addition, SWV values also decreased significantly in 15/16 skin sites with local normal Rodnan at baseline, whereas local Rodnan skin score only changed significantly in the upperarm (p=0.046) and forearm (p=0.026). Conclusion This study provides first-time evidence suggesting that skin SWV values are more sensitive to change over time than mRSS, and reduce significantly over time in SSc and normal controls.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound – Part I: Extraarticular Pathologies

“…Compared to clinical evaluation, US examination proved more sensitive and reliable for quantifying systemic sclerosis (SSc) skin involvement in both patients and controls [335][336][337][338][339]. A better discrimination between clinical and subclinical skin involvement [335][336][337][338][339][340], different forms of SSc, and disease stages [335][336][337] was achieved. An inverse relationship between skin echogenicity and thickness was identified in patients with SSc in the edematous phase of the disease [335,336].…”

“…Elastography can quantify skin stiffness by adding information about the disease stage and helping to distinguish subclinical SSc involvement from healthy skin [340,343,344]. Shear wave velocity values were significantly higher in SSc patients than in controls at almost all modified Rodnan Skin Score sites and thus correlated with the degree of pulmonary involvement [339,343].…”