An evaluation of mechanical and biophysical skin parameters at different body locations.

BACKGROUND: Skin is the largest organ in the body, representing an important interface to monitor health and disease. However, there is significant variation in skin properties for different ages, genders and body regions due to the differences in the structure and morphology of the skin tissues. This study aimed to evaluate the use of non-invasive tools to discriminate a range of mechanical and functional skin parameters from different skin sites. MATERIALS AND METHODS: A cohort of 15 healthy volunteers was recruited following appropriate informed consent. Four well-established CE-marked non-invasive techniques were used to measure four anatomical regions: palm, forearm, sole and lower lumbar L3, using a repeated measures design. Skin parameters included trans-epidermal water loss (TEWL), pH (acidity), erythema, stratum corneum hydration and stiffness and elasticity using Myoton Pro (skin and muscle probe). Differences between body locations for each parameter and the intra-rater reliability between days were evaluated by the same operator. RESULTS: The results indicate that parameters differed significantly between skin sites. For the Myoton skin probe, the sole recorded the highest stiffness value of 1006 N/m (SD ± 179), while the lower lumbar recorded the least value of 484 N/m (SD ± 160). The muscle indenter Myoton probe revealed the palm's highest value of 754 N/m (± 108), and the lower lumbar recorded the least value of 208 N/m (SD ± 44). TEWL values were lowest on the forearm, averaging 11 g/m2/h, and highest on the palm, averaging 41 g/m2/h. Similar skin hydration levels were recorded in three of the four sites, with the main difference being observed in the sole averaging 13 arbitrary units. Erythema values were characterised by a high degree of inter-subject variation, and no significant differences between sites or sides were observed. The Myoton Pro Skin showed excellent reliability (intra-class correlation coefficients > 0.70) for all sites with exception of one site right lower back; the Myoton pro muscle probes showed good to poor reliability (0.90-017), the corneometer showed excellent reliability (>0.75) among all the sites tested, and the TEWL showed Good to poor reliability (0.74-0.4) among sites. CONCLUSION: The study revealed that using non-invasive methods, the biophysical properties of skin can be mapped, and significant differences in the mechanical and functional properties of skin were observed. These parameters were reliably recorded between days, providing a basis for their use in assessing and monitoring changes in the skin during health and disease.

Change in calcinosis over 1 year using the scleroderma clinical trials consortium radiologic scoring system for calcinosis of the hands in patients with systemic sclerosis.

INTRODUCTION: Calcinosis cutis is a debilitating complication of systemic sclerosis (SSc). We previously developed a radiographic scoring system to assess severity of calcinosis affecting the hands in patients with SSc. We sought to further validate our radiographic scoring system to assess for change over 1 year and to identify factors associated with improvement or progression. MATERIALS AND METHODS: Baseline and 1-year antero-posterior hand radiographs were obtained in 39 SSc patients with calcinosis prospectively enrolled at 6 centers within the US, Canada, Mexico and Australia. Two readers (one radiologist and one rheumatologist) scored all radiographs using the calcinosis scoring system and a 5-point Likert scale (1 = A lot better, 2 = A little better, 3=No change, 4 = A little worse, 5 = A lot worse) on follow-up. By maximizing the Kappa coefficient of agreement between grouped Likert scale (better/no change/worse) and the percentage of change of calcinosis in the radiographic scoring system, we defined progressive calcinosis as >25% increase in score from baseline at 1-year, stable calcinosis as change in score between -25% to 25%, and improvement of calcinosis as decrease in score by >25%. Nineteen SSc patients from an independent cohort were used for validation. RESULTS: Inter-rater reliability of the calcinosis scoring system was high with intra-class correlation coefficient of 0.93 (0.89-0.95). The median percentage of change from baseline to 1 year was 12.8% (range -89.3 to 290.2%). Sixteen patients (41%) experienced progression of calcinosis over 1 year; 18 (46%) remained stable; and 5 (13%) had improvement. Patients with progressive calcinosis had lower T-score on bone densitometry (-3.3 vs -1.7, p = 0.044) and higher prevalence of loss of digital pulp on physical exam (56% vs 22%, p = 0.027), with a trend towards lower baseline modified Rodnan skin score (mRSS) (3.8 vs. 5.9, p = 0.057), than patients who did not progress. Patients who experienced improvement in calcinosis had lower prevalence of digital pitting scars (20% vs 71%, p = 0.047) than patients whose calcinosis did not improve. In multivariable analysis, loss of digital pulp remained a predictor of calcinosis progression (OR 5.8, p = 0.023, CI 1.27 - 26.36). In the validation cohort, 2 (11%) patients improved, 10 (53%) remained stable, and 7 (37%) progressed. CONCLUSIONS: We confirmed the excellent inter-rater reliability of our radiographic calcinosis scoring system and demonstrated its usefulness to detect change over time. Approximately 40% of patients experienced progression of calcinosis over 1 year. Loss of digital pulp was predictive of progressive calcinosis providing further evidence that digital ischemia contributes to the progression of calcinosis.

Ultrasound and elastography in the assessment of skin involvement in systemic sclerosis: A systematic literature review focusing on validation and standardization - WSF Skin Ultrasound Group.

OBJECTIVE: To summarize the published evidence in the literature on the role of ultrasound and elastography to assess skin involvement in systemic sclerosis (SSc). METHODS: A systematic literature review (SLR) was performed within the "Skin Ultrasound Working Group" of the World Scleroderma Foundation, according to the Cochrane Handbook. A search was conducted in Pubmed, Cochrane Library and Embase databases from 1/1/1979 to 31/5/2021, using the participants, intervention, comparator and outcomes (PICO) framework. Only full-text articles involving adults, reported in any language, assessing ultrasound to quantify skin pathology in SSc patients. Two reviewers performed the assessment of risk of bias, data extraction and synthesis, independently. RESULTS: Forty-six studies out of 3248 references evaluating skin ultrasound and elastography domains were included. B-mode ultrasound was used in 30 studies (65.2%), elastography in nine (19.6%), and both methods in seven (15.2%). The ultrasound outcome measure domains reported were thickness (57.8%) and echogenicity (17.2%); the elastography domain was stiffness (25%). Methods used for image acquisition and analysis were remarkably heterogeneous and frequently under-reported, precluding data synthesis across studies. The same applies to contextual factors and feasibility. Our data syntheses indicated evidence of good reliability and convergent validity for ultrasound thickness evaluation against mRSS and skin histological findings. Stiffness and echogenicity have limited evidence for validity against histological findings. Evidence for sensitivity to change, test-retest reliability, clinical trial discrimination or thresholds of meaning is limited or absent for reported ultrasound domains. CONCLUSION: Ultrasound is a valid and reliable tool for skin thickness measurement in SSc but there are significant knowledge gaps regarding skin echogenicity assessment by ultrasound and skin stiffness evaluation by elastography in terms of feasibility, validity and discrimination. Standardization of image acquisition and analysis is needed to foster progress.

Symptom experience of limited cutaneous systemic sclerosis from the Patients' perspective: A qualitative study✰,✰✰,☠,☠☠.

OBJECTIVES: Limited cutaneous systemic sclerosis (lcSSc) is the largest subgroup of people with SSc, but little is known about symptom experience from the patients' perspective. This study aimed to comprehensively identify domains and symptoms reported as bothersome by patients with lcSSc and to analyze themes and sub-themes capturing symptom experience in this population. METHODS: Focus groups of patients with lcSSc were conducted using a structured guide. Patients were recruited based on an a priori purposive framework to include men and women with SSc. Focus groups were recorded, transcribed, anonymized, and analyzed using the RADaR technique (rigorous and accelerated data reduction) combined with iterative, deductive and inductive approaches. RESULTS: Four 2-hour Focus groups comprising participants with lcSSc were conducted (N = 26). Ninety-four symptoms were identified with 22 domains. Symptoms from the following domains were mentioned in all Focus groups: skin, musculoskeletal (MSK), cardiac, pulmonary, gastro-intestinal (GI) manifestations, fatigue, sleep, Raynaud's phenomenon (RP), pain, and digital ulcers. The three most cited domains in a pre-meeting survey were GI, RP and MSK. Seven themes defining symptom experience were identified: difficulty attributing symptoms to this complex systemic disease, influence of symptom temporality, impairment of emotional well-being, limitations in functioning (including several sub-themes of functioning), survival, symptoms management and uncertainty. CONCLUSION: This study comprehensively identified domains and symptoms considered bothersome from the perspective of patients with lcSSc and summarized patient experience of lcSSc-related symptoms. This study is the first step in the design of a future combined response index dedicated to lcSSc that could foster specific research on this subpopulation of patients.

Cellular and Molecular Diversity in Scleroderma.

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.