HIGH FREQUENCY ULTRASONOGRAPHY: RELIABLE TOOL TO MEASURE SKIN FIBROSIS IN SSC? A systematic literature review and additional pilot study

Ultrasound measurement of traumatic scar and skin thickness: a scoping review of evidence across the translational pipeline of research-to-practice

OBJECTIVES

To identify the ultrasound methods used in the literature to measure traumatic scar thickness, and map gaps in the translation of these methods using evidence across the research-to-practice pipeline.

DESIGN

Scoping review.

DATA SOURCES

Electronic database searches of Ovid MEDLINE, Embase, Cumulative Index of Nursing and Allied Health Literature and Web of Science. Grey literature searches were conducted in Google. Searches were conducted from inception (date last searched 27 May 2022).

DATA EXTRACTION

Records using brightness mode (B-mode) ultrasound to measure scar and skin thickness across the research-to-practice pipeline of evidence were included. Data were extracted from included records pertaining to: methods used; reliability and measurement error; clinical, health service, implementation and feasibility outcomes; factors influencing measurement methods; strengths and limitations; and use of measurement guidelines and/or frameworks.

RESULTS

Of the 9309 records identified, 118 were analysed (n=82 articles, n=36 abstracts) encompassing 5213 participants. Reporting of methods used was poor. B-mode, including high-frequency (ie, >20 MHz) ultrasound was the most common type of ultrasound used (n=72 records; 61% of records), and measurement of the combined epidermal and dermal thickness (n=28; 24%) was more commonly measured than the epidermis or dermis alone (n=7, 6%). Reliability of ultrasound measurement was poorly reported (n=14; 12%). The scar characteristics most commonly reported to be measured were epidermal oedema, dermal fibrosis and hair follicle density. Most records analysed (n=115; 97%) pertained to the early stages of the research-to-practice pipeline, as part of research initiatives.

CONCLUSIONS

The lack of evaluation of measurement initiatives in routine clinical practice was identified as an evidence gap. Diverse methods used in the literature identified the need for greater standardisation of ultrasound thickness measurements. Findings have been used to develop nine methodological considerations for practitioners to guide methods and reporting.

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.

Systemic sclerosis

Systemic sclerosis, also known as scleroderma, is a rare and complex autoimmune connective-tissue disease. Once considered an untreatable and unpredictable condition, research advancements have improved our understanding of its disease pathogenesis and clinical phenotypes and expanded our treatment armamentarium. Early and accurate diagnosis is essential, while ongoing efforts to risk stratify patients have a central role in predicting both organ involvement and disease progression. A holistic approach is required when choosing the optimal therapeutic strategy, balancing the side-effect profile with efficacy and tailoring the treatment according to the goals of care of the patient. This Seminar reviews the multiple clinical dimensions of systemic sclerosis, beginning at a precursor very early stage of disease, with a focus on timely early detection of organ involvement. This Seminar also summarises management considerations according to the pathological hallmarks of systemic sclerosis (eg, inflammation, fibrosis, and vasculopathy) and highlights unmet needs and opportunities for future research and discovery.

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.

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

Objective

Ultrasound is a promising tool to foster much-needed improvement of skin assessment in systemic sclerosis (SSc). Our aim was to develop evidence and expert opinion-based recommendations to promote the standardisation and harmonisation of technical execution and reporting of skin ultrasound studies in SSc.

Methods

A multidisciplinary task force of 16 members from five European countries and Japan was convened under the auspices of World Scleroderma Foundation. First, a systematic literature review (SLR) was performed. Then, each member proposed and formulated items to the overarching principles, recommendations and research agenda. Two rounds of mails exchange for consensus as well as an on-line meeting were performed to debate and refine the proposals. Two Delphi rounds of voting resulted in the final recommendations. Levels of evidence and strengths of recommendations were assigned, and task force members voted anonymously on the level of agreement with each of the items.

Results

Five overarching principles and seven recommendations were developed, based on an SLR and expert opinion, through consensus procedures. The overarching principles highlight the promising role of skin ultrasound in SSc assessment, the need for standardisation of technical aspects, sufficient training and adequate equipment. The recommendations provide standards for the execution and reporting of skin ultrasound in SSc. The research agenda includes the need for more research into unmet needs according to Outcome Measures in Rheumatology Algorithm requirements.

Conclusion

These are the first recommendations providing guidance on the execution and reporting of skin ultrasound in SSc patients, aiming at improving the interpretability, reliability and generalisability of skin ultrasound, thus consolidating its role in research and practice.