Nailfold videocapillaroscopy in the assessment of juvenile connective tissue diseases

To evaluate nailfold videocapillaroscopy (NVC) findings in paediatric patients with primary Raynaud's phenomenon (pRP) and connective tissue diseases (CTDs). We aimed to assess potential associations between NVC features and clinical/organ involvement in juvenile CTDs.

NVC was performed in children with pRP and in those with CTDs - including juvenile systemic sclerosis (JSSc), dermatomyositis (JDM), and systemic lupus erythematosus (JSLE) - regardless of RP status, all of whom were followed at our Paediatric Rheumatology Unit. For each patient, 32 images were acquired, and microvascular alterations were analysed and classified as either non-specific or scleroderma patterns (early, active, and late) by two independent observers. A semiquantitative rating scale was adopted to score six capillary abnormalities.

A total of 1600 NVC images from 50 subjects (30 females; mean age 16.4±4.0 years) were evaluated. Scleroderma pattern was significantly more frequent in JSSc vs. pRP (p<0.001) and JDM (p<0.005). Differences in capillaroscopic alterations were observed only between pRP and JSSc for reduced capillary density (p<0.001) and presence of giants (p=0.01). Scleroderma pattern was associated with skin fibrosis (21/25 vs. 0/9; p<0.001) and gastrointestinal involvement (17/25 vs. 1/9; p=0.006), with a trend towards significance for digital ulcers (8/25 vs. 0/9; p=0.07). A significantly higher avascular score was found in patients with interstitial lung disease (ILD) than in those without (0.69±0.51 vs. 0.44±0.38; p=0.048). Indeed, patients with severe reduction of capillary density (≤4 capillaries/millimetre) were more likely to have ILD (5/10 vs. 4/13; p=0.02).

NVC is a valuable tool for differentiating pRP from early juvenile CTDs and may help risk stratification for organ involvement, particularly ILD.