We conducted a systematic review, on behalf of the EULAR Study Group on Microcirculation in Rheumatic Diseases (EULAR SG MC/RD), to investigate the value of nailfold videocapillaroscopy (NVC) in idiopathic inflammatory myopathies (IIM).

Three electronic databases were systematically searched to find all relevant manuscripts reporting NVC outcomes in IIM patients. Articles were assessed based on study design, population, NVC methodology and description of NVC results. To allow comparison between the articles, all NVC results were interpreted according to standardised capillaroscopic terminology, as previously consented by the EULAR SG MC/RD and the Scleroderma Clinical Trials Consortium (SCTC) Group on Capillaroscopy.

Of the 653 identified records; five were retained after critical appraisal on title, abstract and manuscript level. A marked difference in NVC was observed between (juvenile) dermatomyositis [(j)DM] versus polymyositis, healthy controls and systemic sclerosis patients. In addition, reduced capillary density and scleroderma pattern seem to be associated with active disease in (j)DM, while immunosuppressive treatment appears to reduce NVC abnormalities.

This is the first systematic review investigating NVC in IIM, interpreting the results according to an international consented standardised manner, as proposed by the EULAR SG MC/RD and SCTC Group on Capillaroscopy. We can conclude that NVC presents a promising asset in the diagnosis of (j)DM. Moreover, NVC could be a biomarker for organ involvement and follow-up. Large multicentre prospective standardised studies are further needed to definitely describe associations with clinical and laboratory parameters in the different IIM subtypes.