Supplementary Material for: Scanning Acoustic Microscopy as a Novel Quantitative Tool for Assessing Dermal Sclerosis in Systemic Sclerosis: A Case Report

Introduction: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by skin fibrosis and internal organ involvement. Quantitative methods for assessing skin sclerosis beyond the modified Rodnan Skin Score (mRSS) are required to better monitor disease progression and treatment response.
Case presentation: A 61-year-old woman with rapidly progressing SSc and early interstitial lung disease was treated with IVCY. Skin biopsies were obtained before and after treatment. SAM was used to measure the speed of sound within the skin tissue, reflecting tissue stiffness. A histological analysis was performed.
Following IVCY, SAM significantly decrease the speed of sound within the affected skin tissue, preceding a measurable reduction in mRSS. Histological analysis showed improvements in collagen bundle architecture and reduced inflammatory cell infiltration.
Conclusion: SAM may be a promising, objective, and quantitative technique for evaluating skin sclerosis in patients with SSc and for monitoring early therapeutic responses. This is an exploratory observation based on a single case. Further investigations in larger, controlled clinical trials are warranted to determine its clinical utility and predictive value.