Recommendations for the execution and reporting of skin ultrasound in systemic sclerosis: an international collaboration under the WSF skin ultrasound group

Skin Ultrasound Assessment of Patients with Systemic Scleroderma-An Observational Study

This study aims to analyze the changes in dermal thickness in patients with systemic scleroderma (SSc) in comparison with normal skin and also compare clinical forms with diffuse and limited cutaneous involvement. The study group consisted of female patients diagnosed with SSc with a disease history not exceeding 5 years. The areas of interest for ultrasound examination included the proximal phalanx of the third finger, the second intermetacarpal space, and the extension surface of the lower third of the forearm. The study included 20 patients diagnosed with SSc and 14 controls. SSc patients were subdivided into two subgroups based on the clinical form. Compared to the control group, patients with SSc had higher mean measurements in all three skin areas, with statistically significant differences in the hand and forearm areas. Patients with diffuse SSc displayed, on average, higher skin thickness compared to limited SSc in all skin areas examined, with a statistically significant difference only in the forearm area. Based on disease manifestations, significant differences were observed only with regard to the presence of pulmonary hypertension in the diffuse SSc group. In conclusion, skin ultrasound is a useful and accessible imaging method for diagnosing and quantifying dermal fibrosis in systemic scleroderma.

Diagnosing vasculitis with ultrasound: findings and pitfalls

Rheumatologists are increasingly utilizing ultrasound for suspected giant cell arteritis (GCA) or Takayasu arteritis (TAK). This enables direct confirmation of a suspected diagnosis within the examination room without further referrals. Rheumatologists can ask additional questions and explain findings to their patients while performing ultrasound, preferably in fast-track clinics to prevent vision loss. Vascular ultrasound for suspected vasculitis was recently integrated into rheumatology training in Germany. New European Alliance of Associations for Rheumatology recommendations prioritize ultrasound as the first imaging tool for suspected GCA and recommend it as an imaging option for suspected TAK alongside magnetic resonance imaging, positron emission tomography and computed tomography. Ultrasound is integral to the new classification criteria for GCA and TAK. Diagnosis is based on consistent clinical and ultrasound findings. Inconclusive cases require histology or additional imaging tests. Robust evidence establishes high sensitivities and specificities for ultrasound. Reliability is good among experts. Ultrasound reveals a characteristic non-compressible 'halo sign' indicating intima-media thickening (IMT) and, in acute disease, artery wall oedema. Ultrasound can further identify stenoses, occlusions and aneurysms, and IMT can be measured. In suspected GCA, ultrasound should include at least the temporal and axillary arteries bilaterally. Nearly all other arteries are accessible except the descending thoracic aorta. TAK mostly involves the common carotid and subclavian arteries. Ultrasound detects subclinical GCA in over 20% of polymyalgia rheumatica (PMR) patients without GCA symptoms. Patients with silent GCA should be treated as GCA because they experience more relapses and require higher glucocorticoid doses than PMR patients without GCA. Scores based on intima-thickness (IMT) of temporal and axillary arteries aid follow-up of GCA, particularly in trials. The IMT decreases more rapidly in temporal than in axillary arteries. Ascending aorta ultrasound helps monitor patients with extracranial GCA for the development of aneurysms. Experienced sonologists can easily identify pitfalls, which will be addressed in this article.

Untangling the relationship between smoking and systemic sclerosis: an analysis of the EUSTAR cohort

OBJECTIVES

To untangle the association between smoking and systemic sclerosis (SSc).

METHODS

In the European Scleroderma Trials and Research cohort, the autoantibody status was compared between ever-smokers and never-smokers. Time until disease progression was assessed using Kaplan-Meier curves. Cox models were built to investigate the influence of smoking over 15 years of follow-up. All analyses were performed for the total cohort and stratified for sex and for positivity of anti-centromere (ACA) and anti-topoisomerase antibodies (ATA).

RESULTS

Overall, 12 314 patients were included in the study. Of these, 10 393 were women (84%), 4637 were ACA-positive (38%), 3919 were ATA-positive (32%) and 4271 (35%) were ever-smokers. In men, but not in women, smoking was associated with mortality (HR 1.63, 95% CI 1.23 to 2.16, p=0.001). Ever-smoking women were at higher risk for skin progression (HR 1.10, 95% CI 1.00 to 1.22, p=0.046) and for 'any organ progression' (HR 1.07, 95% CI 1.00 to 1.13, p=0.036). In women, 34% of never-smokers were ATA-positive compared with 21% of ever-smokers (p<0.001). In the group of ever-smokers, higher exposure rates, reflected by the number of pack-years (OR 0.98, 95% CI 0.97 to 0.99, p<0.001) and by smoking duration (OR 0.96, 95% CI 0.95 to 0.97, p<0.001), were associated with lower frequency of ATA. In ACA-positive patients, the risk of mortality (HR 1.29, 95% CI 1.02 to 1.63, p=0.033), cardiac involvement (HR 1.25, 95% CI 1.03 to 1.43, p=0.001), skin progression (HR 1.21, 95% CI 1.03 to 1.42, p=0.018) and 'any organ progression' (HR 1.14, 95% CI 1.05 to 1.24, p=0.002) was increased among smokers. In ATA-positive smoking patients, mortality (HR 1.40, 95% CI 1.10 to 1.78, p=0.006), skin progression (HR 1.19, 95% CI 1.03 to 1.37, p=0.020) digital ulcers (HR 1.17, 95% CI 1.02 to 1.34, p=0.029) and 'any organ progression' (HR 1.11, 95% CI 1.00 to 1.22, p=0.048) occurred more frequently.

CONCLUSIONS

Our stratified analysis demonstrates that smoking is associated with an increased risk for mortality in male SSc patients but not in women. Strikingly, smoking is associated with lower prevalence of ATA positivity, in particular in women. In both ATA-positive and ACA-positive patients, smoking is a risk factor for mortality, skin progression and 'any organ progression'.

Is cyclophosphamide still the gold standard in early severe rapidly progressive systemic sclerosis?

Cyclophosphamide (CYC) has been a gold standard of treatment for severe progressive Systemic Sclerosis (SSc), especially in patients with concomitant interstitial lung disease (ILD). This approach was based on results of several interventional studies, including randomized control trials, which mainly addressed SSc-ILD as a primary end point and skin involvement as a second one. The use of CYC is time-limited due to significant adverse events. More recently, other immunosuppressive and biological agents showed efficacy but better safety profile in patients with SSc and SSc-ILD. With regards to other end-points, post-hoc analyses, systematic reviews and metalysis showed that CYC had limited influence on patients' quality of life, event-free survival and mortality. Comprehensive patient's stratification according to a molecular, cellular and phenotypic pattern may help in choosing of personalized medicine with more ambitious treatment effect and should be the future direction. According to the above available data and even if scientific evidence may be missing, experts' opinion has changed the attitude to CYC as an anchor drug in the management of severe SSc. Indeed, CYC has been pushed to the second and even third treatment option after mycophenolate mofetil, tocilizumab or rituximab. This position became obvious during debate on this topic at CORA meeting 2023.

A stretchable hardness sensor for the assessment of skin disease in systemic sclerosis

OBJECTIVE

To determine the validity of a hardness sensor to objectively assess skin induration in patients with systemic sclerosis, and to compare the hardness sensor with the modified Rodnan skin score (MRSS) and a durometer.

METHODS

The skin induration was measured in two assessments: a Latin square experiment to examine the hardness sensor's intraobserver and interobserver reliability; and a longitudinal cohort to evaluate the distribution of hardness sensor measurements, the correlation between hardness sensor, durometer and MRSS, and the sensitivity to change in skin hardness. Other outcome data collected included the health assessment questionnaire (HAQ) disability index and Keitel function test (KTF) score.

RESULTS

The reliability of the hardness sensor was excellent, with high intraobserver and interobserver intraclass correlation coefficients (0.97; 0.96), which was higher than MRSS (0.86; 0.74). Interobserver reproducibility of hardness sensor was only poor in abdomen (0.38), yet for durometer it was poor in face (0.11) and abdomen (0.33). The hardness sensor score provided a greater dynamic evaluation range than MRSS. Total hardness sensor score correlated well with MRSS (r=0.90, p<0.001), total durometer score (r=0.95, p<0.001), HAQ disability index (r=0.70, p<0.001) and KTF score (r=0.66, p<0.001). Change in hardness sensor score also correlated with change in MRSS (r=0.78, p<0.001), total durometer score (r=0.85, p<0.001), HAQ disability index (r=0.76, p<0.001) and KTF score (r=0.67, p<0.001).

CONCLUSION

The hardness sensor showed greater reproducibility and accuracy than MRSS, and more application sites than durometer; it can also reflect patients' self-assessments and function test outcomes.

The role of skin ultrasound in systemic sclerosis: looking below the surface to understand disease evolution

Skin ultrasound has shown promising results in the evaluation of skin involvement in patients with systemic sclerosis, as substantiated by a recent systematic literature review from the World Scleroderma Foundation Skin Ultrasound Working Group. In this Viewpoint, we will discuss the role of ultrasound in evaluating skin involvement in patients with systemic sclerosis, particularly the possibility of using this technique to detect an early subclinical skin involvement from the very early phase, suggesting its possible use in both diagnosis and disease follow-up. To detect subclinical skin involvement, it is essential to understand the difference between the skin of patients with systemic sclerosis and that of healthy controls, including defining exactly which structures are affected by the disease and which are spared. The potential of this non-invasive technique might suggest its future role in both clinical practice and clinical trials, possibly replacing invasive and painful procedures such as skin biopsies and promoting patient retention in clinical trials.

Normal percentile reference curves for skin ultrasound thickness and stiffness at Rodnan sites

Objectives

Our primary objective was to establish preliminary normal reference curves for ultrasound–dermal thickness and skin stiffness in the 17 Rodnan skin sites, considering the effect of gender and age on these measures. As an exploratory objective, we investigated the effect of body mass index and the menopause on skin ultrasound measures.

Methods

A cross-sectional study was conducted involving 140 healthy volunteers, aged 20–79 years. Recruitment was stratified by gender and age (10-year categories). Ultrasound–dermal thickness and skin stiffness were assessed by high-frequency ultrasound and shear-wave elastography, respectively, at the 17 Rodnan skin sites. Outcomes were evaluated through a mixed linear model, univariate and multivariate regressions. Normal reference curves were derived for both ultrasound measures in each skin site. An online calculator of the percentiles of skin ultrasound measures was developed.

Results

Ultrasound–dermal thickness and stiffness measures were higher in men than women in all Rodnan skin sites (except in chest for ultrasound–dermal thickness). Age had also a significant impact in both ultrasound measures, but only in some skin sites. Gender and age percentile curves (97.5th, 95th, 75th, 50th, 25th, 5th, 2.5th) were plotted for each of the measures in each skin site.

Conclusions

Gender and age are strongly associated with skin ultrasound parameters, imposing the need for gender-specific and age-specific reference values. Normal reference percentile curves are provided as a basis for future cooperative work to strengthen its evidence basis, representativeness and refinement regarding potentially influential factors.