Footnotes

• Contributors The manuscript has been seen and approved by all the authors who have given necessary attention to ensure the integrity of the work.

• Funding This study was financially supported by funding of the Research Laboratory and Academic Division of Rheumatology of the University of Genova, Italy.

• Competing interests None.

• Patient consent Obtained.

• Ethics approval Ethics approval was obtained from local ethical board.

• Provenance and peer review Not commissioned; externally peer reviewed.

• Data sharing statement This study demonstrates that blood perfusion is significantly lower in patients with SSc than in healthy subjects at the level of fingertips, periungual and palm areas, but not at face and dorsum of hands, explaining the highest risk and prevalence of skin ulcers in those areas.