Scientific Evidence & Guidelines
Curated guidelines, reviews, methodological papers, and key studies showing what currently supports capillaroscopy in practice and research.
Core evidence and critical context
This page brings together the references that are most useful if you want to understand what currently supports capillaroscopy: methodological standards, synthesis reviews, reproducibility studies, Raynaud and systemic sclerosis registries, and emerging work on quantification and artificial intelligence.
It is not intended to replace an exhaustive bibliography. The goal is to provide a prioritized reading structure: which references deserve early attention, which ones influence daily practice, which ones guide research design, and where the evidence remains preliminary.
How to read the evidence
Established
Standardized technique, use in Raynaud's phenomenon and systemic sclerosis, and the need for reproducible reporting language.
Useful but contextual
Prognostic value, connective tissue diseases beyond systemic sclerosis, and longitudinal follow-up, where clinical context matters greatly.
Emerging
Quantification, AI, pediatrics, and applications beyond core rheumatology, with growing but uneven support depending on the question.
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Essential reading
If a high-yield starting set is needed, these references provide the strongest base for clinical work, teaching, and protocol design.
Reference broad review
Smith V, Ickinger C, Hysa E, Snow M, Frech T, Sulli A, et al. Nailfold capillaroscopy. Best Pract Res Clin Rheumatol. 2023;37(1):101849.
Probably the best single entry point into the field. It summarizes indications, patterns, limitations, and future directions with a broad clinical view.
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Reference methodological paper
Smith V, Herrick AL, Ingegnoli F, Damjanov N, De Angelis R, Denton CP, et al. Standardisation of nailfold capillaroscopy for the assessment of patients with Raynaud's phenomenon and systemic sclerosis. Autoimmun Rev. 2020;19(3):102458.
It is the key reference for environment, acquisition, finger selection, patient preparation, and shared language across centers.
Key registry on Raynaud and progression to systemic sclerosis
Bellando-Randone S, Del Galdo F, Lepri G, Minier T, Huscher D, Furst DE, et al. Progression of patients with Raynaud's phenomenon to systemic sclerosis: a five-year analysis of the European Scleroderma Trial and Research group multicentre, longitudinal registry study for Very Early Diagnosis of Systemic Sclerosis (VEDOSS). Lancet Rheumatol. 2021;3(12):e834-e843.
It clarifies why capillaroscopy changes risk stratification in Raynaud's phenomenon when integrated with autoantibodies and follow-up.
Classic reliability study
Dinsdale G, Moore T, O'Leary N, Tresadern P, Berks M, Roberts C, et al. Intra- and inter-observer reliability of nailfold videocapillaroscopy: a possible outcome measure for systemic sclerosis-related microangiopathy. Microvasc Res. 2017;112:1-6.
It remains one of the clearest reminders that the technique is only useful when definitions and training support reproducible reading.
The practical reference for structured reporting
El Miedany Y, Ismail S, Wadie M, Müller-Ladner U, Giacomelli R, Liakouli V, et al. Development of a core domain set for nailfold capillaroscopy reporting. Reumatol Clin (Engl Ed). 2024;20(7):345-352.
Very useful if you want to move from describing images to building comparable reports for clinic and longitudinal follow-up.
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Guidelines, criteria, and reference documents
This section gathers the texts that structure practice: classification, methodological standardization, and broad clinical utility.
2013 ACR/EULAR systemic sclerosis criteria
van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthritis Rheum. 2013;65(11):2737-2747.
Not a technique paper, but it explains why capillaroscopic abnormalities became a structural part of classification reasoning in systemic sclerosis.
Practice-oriented clinical utility review
Roberts-Thomson PJ, Patterson KA, Walker JG. Clinical utility of nailfold capillaroscopy. Intern Med J. 2023;53(5):671-679.
A useful summary of which clinical questions capillaroscopy can answer and where it should not be overstated.
Core domain set for reporting
El Miedany Y, Ismail S, Wadie M, Müller-Ladner U, Giacomelli R, Liakouli V, et al. Development of a core domain set for nailfold capillaroscopy reporting. Reumatol Clin (Engl Ed). 2024;20(7):345-352.
It is especially useful for building a reporting template or harmonizing output across clinicians and projects.
Reproducibility, training, and image quality
This is the literature that explains why capillaroscopy requires protocol, training, and quality control in order to be comparable.
Intra- and inter-observer reliability
Dinsdale G, Moore T, O'Leary N, Tresadern P, Berks M, Roberts C, et al. Intra- and inter-observer reliability of nailfold videocapillaroscopy: a possible outcome measure for systemic sclerosis-related microangiopathy. Microvasc Res. 2017;112:1-6.
Still one of the clearest references for discussing reader variability, training, and the limits of visual endpoints.
How many fingers should be assessed?
Dinsdale G, Roberts C, Moore T, Manning J, Berks M, Allen J, et al. Nailfold capillaroscopy: how many fingers should be examined to detect abnormality? Rheumatology (Oxford). 2019;58(2):284-288.
A practical paper that is very useful when designing clinical protocols and studies without oversimplifying acquisition.
Raynaud's phenomenon, systemic sclerosis, and prognosis
The clinical center of gravity of the field remains here: Raynaud stratification, systemic sclerosis classification, and vascular prognosis.
VEDOSS and progression from Raynaud's phenomenon
Bellando-Randone S, Del Galdo F, Lepri G, Minier T, Huscher D, Furst DE, et al. Progression of patients with Raynaud's phenomenon to systemic sclerosis: a five-year analysis of the European Scleroderma Trial and Research group multicentre, longitudinal registry study for Very Early Diagnosis of Systemic Sclerosis (VEDOSS). Lancet Rheumatol. 2021;3(12):e834-e843.
This is the reference that best explains why capillaroscopy plus autoantibodies change follow-up in Raynaud that is not clearly primary.
Contemporary reassessment of primary vs secondary Raynaud
Amaral MC, Paula FS, Caetano J, Ames PR, Alves JD. Re-evaluation of nailfold capillaroscopy in discriminating primary from secondary Raynaud's phenomenon and in predicting systemic sclerosis: a randomised observational prospective cohort study. Expert Rev Clin Immunol. 2024;20(6):665-672.
It is useful for reassessing how much a normal capillaroscopy still contributes and how cautiously it should be used in prediction.
Digital ulcer risk and local microangiopathy
Boulon C, Velardo F, Blaise S, Mangin M, Chevoir JD, Senet P, et al. Correlation of nailfold capillaroscopy findings with history of digital ulcer on same finger: Results of SCLEROCAP study. Microvasc Res. 2022;142:104365.
Important for understanding how capillaroscopic reading can move beyond description and start speaking to real vascular burden.
Systemic sclerosis-associated pulmonary hypertension
Minopoulou I, Theodorakopoulou M, Boutou A, Arvanitaki A, Pitsiou G, Doumas M, et al. Nailfold Capillaroscopy in Systemic Sclerosis Patients with and without Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis. J Clin Med. 2021;10(7):1528.
Useful if you want to position capillaroscopy within cardiopulmonary risk rather than oversell it as a replacement for standard screening.
Quantification, automation, and artificial intelligence
These references are particularly useful for separating solid methodological innovation from technological overstatement.
External clinical validation of automated software
Gracia Tello BC, Ramos Ibañez E, Saez Comet L, Guillén Del Castillo A, Simeón Aznar CP, Selva-O'Callaghan A, et al. External clinical validation of automated software to identify structural abnormalities and microhaemorrhages in nailfold videocapillaroscopy images. Clin Exp Rheumatol. 2023;41(8):1605-1611.
One of the most useful papers for discussing external validation and performance under real clinical conditions rather than only development datasets.
CAPI-score
Gracia Tello BDC, Sáez Comet L, Lledó G, Freire Dapena M, Mesa MA, Martín-Cascón M, et al. Capi-score: a quantitative algorithm for identifying disease patterns in nailfold videocapillaroscopy. Rheumatology (Oxford). 2024;63(12):3315-3321.
Important because it shifts the conversation from purely visual recognition toward reproducible quantification and decision support.
CAPI-Detect
Lledó-Ibáñez GM, Sáez Comet L, Freire Dapena M, Mesa Navas M, Martín Cascón M, Guillén Del Castillo A, et al. CAPI-Detect: machine learning in capillaroscopy reveals new variables influencing diagnosis. Rheumatology (Oxford). 2025;64(6):3667-3675.
Useful for understanding that AI does not only classify; it can also reveal diagnostic variables that must then be clinically reinterpreted.
Vision transformer for screening assistance
Garaiman A, Nooralahzadeh F, Mihai C, Gonzalez NP, Gkikopoulos N, Becker MO, et al. Vision transformer assisting rheumatologists in screening for capillaroscopy changes in systemic sclerosis: an artificial intelligence model. Rheumatology (Oxford). 2023;62(7):2492-2500.
A good example of assistive AI: useful for screening and triage, but not a replacement for validation, image quality, or clinical supervision.
Beyond core rheumatology
These references help extend the focus beyond the Raynaud-systemic sclerosis axis and assess where the technique carries relevant signal in other contexts.
Structured review in idiopathic inflammatory myopathies
Piette Y, Reynaert V, Vanhaecke A, Bonroy C, Gutermuth J, Sulli A, et al. Standardised interpretation of capillaroscopy in autoimmune idiopathic inflammatory myopathies: A structured review on behalf of the EULAR study group on microcirculation in Rheumatic Diseases. Autoimmun Rev. 2022;21(6):103087.
Probably the best single reading to position what capillaroscopy can and cannot say in dermatomyositis and other inflammatory myopathies.
Worldwide standardized pediatric study
Melsens K, Cutolo M, Schonenberg-Meinema D, et al. Standardized nailfold capillaroscopy in children with rheumatic diseases: a worldwide study. Rheumatology (Oxford). 2023;62(4):1605-1615.
Valuable because it provides an international methodological frame for interpreting normality and disease in children.
Meta-analysis in diabetes
He W, Zhang M, Mao R, Han C, Shi L, Wu H. Association between nailfold capillaroscopic findings and diabetes: a systematic review and meta-analysis. Acta Diabetol. 2025;62(7):983-999.
A good summary of why diabetes is now a promising research line rather than an established clinical indication.
How this section is curated
This selection prioritizes guidelines, consensus papers, systematic reviews, multicenter studies, and methodological articles that change how capillaroscopy is acquired, reported, or applied. When an area remains emerging, it is explicitly presented as such rather than as established practice.
Last updated: March 6, 2026