Role of skin ultrasound in diagnosis of systemic sclerosis compared to Modified Rodnan skin score, inflammatory marker and disease activity indices

Abstract

The goal of this study To assess if high frequency ultrasound correlates with modified Rodnan skin score and inflammatory markers and if it can differentiate between Systemic sclerosis and healthy individuals and if HFU can detect subclinical skin thickening. We recruited 30 consecutive patients with SSc and 40 controls in this case control study. Skin thickness was measured by 20-22 MHz ultrasonic probe at 3 different skin sites bilaterally (at third proximal interphalyngeal, third metacarpophalyngeal and wrist joints bilaterally). Total skin thickness (TST) by HFU and skin thickness using mRSS were recorded and compared to HFU.The final results of our work show that total skin thickness in patients with SSc was higher than in healthy controls (P < 0.001), and correlated positively with total mRSS and correlated negatively with CRP. Patients with higher TST had higher mRSS . The area under the receiver operator characteristic (ROC) curve yielded sensitivity of 90% and specificity of 85% at the predicted probability of 1.4 mm as the optimal cut off point to access of mean skin thickness.

Keywords

• systemic sclerosis
• high frequency ultrasound
• skin thickness