• Rheumatology Clinical Trials
• Rheumatological Autoimmune Disorders

• Rheumatology Clinical Trials
• Rheumatological Autoimmune Disorders
• Rheumatology

Systemic sclerosis (SSc) is characterized by increased dermal thickness (DT); the severity and extent of skin involvement are used to establish the diagnosis and subclassify the disease. The modified Rodnan skin score (mRSS) is a validated method to evaluate skin involvement in SSc, and it is based on manual palpation of 17 areas of the skin. Alberto Sulli, MD, University of Genova, Genoa, Italy, discussed detection of subclinical diffuse dermal involvement by high-frequency ultrasound (US) in patients with limited cutaneous SSc (lcSSc) and presented a poster on the correlation among 3 different methods: mRSS, high-frequency ultrasound (US; a 18-MHz probe), and a plicometer skin test (plicometry) to evaluate skin involvement in patients with SSc [Ruaro B et al. EULAR 2014 (poster SAT0304)].

In patients with lcSSc, areas of skin that were normal according to mRSS were evaluated by high-frequency US. The aim of the study of mRSS, high-frequency US, and plicometry in patients with SSc was to identify possible correlations among these techniques to evaluate DT.

Prof. Sulli presented the results of a study in which 50 patients with lcSSc diagnosed by mRSS (a 5-year median duration of disease) were compared with 50 healthy subjects. DT was evaluated in the 17 standard skin areas (cheeks, fingers, dorsum of hands, forearms, arms, chest, abdomen, thighs, legs, and feet) in patients and healthy control subjects by both mRSS and high-frequency US. He then highlighted a comparative technique study by Ruaro and colleagues [EULAR 2014 (poster SAT0304)], in which the DT of 70 patients with SSc was compared with that of 63 healthy subjects using mRSS, high-frequency US, and plicometry on the standard 17 skin areas. The 3 techniques were performed on the same day for each subject and repeated by 2 blind operators to evaluate interobserver and intraobserver variability.

In patients with lcSSc, DT measured by high-frequency US was significantly higher than DT in healthy subjects for all skin areas (p<0.0001) except the thighs. DT was significantly higher in patients with lcSSc than in healthy subjects in 4 out of 6 skin areas (the arms, chest, and abdomen) in which the mRSS was normal, in agreement with the diagnosis of lcSSc.

In the comparative study, a significant positive correlation was found among the 3 methods used to evaluate DT in patients with SSc (mRSS vs US r=0.53, p<0.0001; mRSS vs plicometry r=0.98, p<0.0001; and US vs plicometry r=0.53, p<0.0001). DT in patients with SSc, including limited and diffuse SSc, was significantly higher (p=0.0001) than that of controls. Interobserver and intraobserver variability was small; variability and execution times for the 3 techniques are shown in Table 1.

These studies show that subclinical diffuse dermal involvement may be detectable by high-frequency US in patients with lcSSc. This may be useful in future disease subclassification and may explain the similar degree of organ involvement in patients with lcSSc and diffuse cutaneous SSc that has been seen in clinical studies. In nearly all 17 skin areas analyzed by high-frequency US, patients with SSc have a significantly higher DT than controls. The 3 techniques of mRSS, high-frequency US, and plicometry used to measure DT in patients with SSc show a high degree of correlation.

• © 2014 MD Conference Express®