Assessment of Skin by High Frequency Musculoskeletal Ultrasound in Egyptian Patients with Systemic Sclerosis
Authors: Moawed Abo Zied Mohamed Abdel Rahman , Abo Gabal Mervat Mamdouh , Morad Caroline Samy , Mohamed Mohamed Rezk 
Published: July 2024

Abstract

Background
Fibrotic involvement of the skin is a cardinal feature of systemic sclerosis (SSc). The extent of skin involvement is associated with internal organ involvement with severe disease course and poor prognosis. SSc skin involvement is characterized by three phases in temporal sequence: edematous, fibrotic, and atrophic. A palpation-based semi- quantitative score, the modified Rodnan skin score (mRSS) is widely used for the assessment of skin involvement. It is a quick, noninvasive clinical assessment that correlates with histological grading of skin fibrosis. However, it lacks the sensitivity to differentiate between clinically indistinguishable pathological phases such as inflammatory edema vs. established fibrosis. More objective approaches to measure skin involvement imaging have been developed in the past decades.In our study, we review the use of ultrasound for the assessment of early changes in skin thickness and echogenicity in patients with SSc, focusing. mainly on high frequency ultrasound.

Aim of the Work
to evaluate the role of high frequency ultrasound (HFUS) of skin in assessment of early changes in skin thickness and echogenicity in patients with SSc.

Patients and Methods
Our study is a cross-sectional, observational study involving homogenous groups consisting of 23 SSc patients and 21 healthy age and sex matched controls. Patients who fulfilled the 2013 ACR/EULAR Classification Criteria for SSc.

Results
DT was evaluated by both mRSS and HFUS at 5 skin areas in both patients and control. We found statistically significant difference between the two studied groups as regards in area 1 longitudinal (P = 0.017) and area 1 in transverse (P = 0.038), tendency to significance in area 2 (P = 0.054). Subclinical dermal involvement was detected by HFUS even in the skin areas in patients who had a normal local MRSS ( These areas were not planned to be assessed by high frequency ultrasound but added to the five areas to be assessed to evaluate for ultrasound detected subclinical involvement of skin in SSc patients ). In particular, DT was highly significantly greater in patients with area with Rodnan zero score at dorsum of hand than in healthy subjects (longitudinal and transverse) (P &lt; 0.001, 0.005 ) respectively. Similar changes at the level of echogenicity occurred in determination of the stage of the disease, with increased skin thickness and decreased echogenicity occurring early and during skin disease activity due to edema; and decrease skin thickness and increased echogenicity occurring late with skin atrophy

Conclusion
that high frequency ultrasound is a useful tool in assessment of skin pathologic changes (even subclinical changes) in terms of thickness and echogenicity in patients with SSc both at disease onset and during follow up of response to therapy and disease stage. Moreover, it could be a useful screening tool with definite cutoff values at certain areas that differentiate normal from pathologic skin thickness.