Standardised nailfold capillaroscopy in children with rheumatic diseases: a worldwide study

To standardly assess and describe nailfold videocapillaroscopy (NVC) assessment in children and adolescents with juvenile rheumatic and musculoskeletal diseases (jRMD) versus healthy controls (HC).In consecutive jRMD children and matched HC from 13 centres worldwide, 16 NVC images per patient were acquired locally and read centrally per international consensus standard evaluation of the EULAR Study Group on Microcirculation in Rheumatic Diseases. 95 patients with juvenile idiopathic arthritis (JIA), 22 with dermatomyositis (JDM), 20 with systemic lupus erythematosus (cSLE), 13 with systemic sclerosis (jSSc), 21 with localized scleroderma (lSc), 18 with mixed connective tissue disease (MCTD) and 20 with primary Raynaud's phenomenon (PRP) were included. NVC differences between juvenile subgroups and HC were calculated through multivariable regression analysis.A total number of 6474 images were assessed from 413 subjects (mean age 12.1-years, 70.9% female). The quantitative NVC-characteristics were significantly lower (↓) or higher (↑) in the following subgroups compared to HC: For density: ↓ in jSSc, JDM, MCTD, cSLE and lSc; For dilations: ↑ in jSSc, MCTD and JDM; For abnormal shapes: ↑ JDM and MCTD; For haemorrhages: ↑ in jSSc, MCTD, JDM and cSLE. The qualitative NVC-assessment of JIA, lSc and PRP did not differ from HC, whereas the cSLE and jSSc, MCTD, JDM, cSLE subgroups showed more non-specific and scleroderma patterns respectively.This analysis resulted from a pioneering registry of NVC in jRMD. The NVC-assessment in jRMD differed significantly from HC. Future prospective follow up will further elucidate the role of NVC in jRMD.