Non-invasive imaging and clinical skin scores in juvenile localised scleroderma

Objectives: To evaluate whether in juvenile localised scleroderma (JLS), non-invasive imaging can differentiate affected from non-affected skin and whether imaging correlates with a validated skin score (Localised Scleroderma Cutaneous Assessment Tool, LoSCAT). Methods: 25 children with JLS were recruited into a prospective study and a single 'target' lesion selected. High frequency ultrasound (HFUS, measuring skin thickness), infrared thermography (IRT, skin temperature), laser Doppler imaging (LDI, skin blood flow) and multispectral imaging (MSI, oxygenation), were performed at four sites: two of affected skin (centre and inner edge of lesion) and two of non-affected skin (one cm from edge of lesion 'outer' and contralateral non-affected side), at 4 visits at 3 monthly intervals. Results: Differences between affected and non-affected skin were detected with all 4 techniques. Compared with non-affected skin, affected skin was thinner (p< 0.001) with higher temperature (p< 0.001-0.006), perfusion (p< 0.001-0.039) and oxygenation (p< 0.001-0.028). Lesion skin activity (LoSCAT) was positively correlated with centre HFUS (r = 0.32; 95% CI [0.02, 0.61]; p= 0.036) and negatively correlated with centre LDI (r=-0.26; 95% CI [-0.49, -0.04]; p= 0.022). Lesion skin damage was positively correlated with centre and inner IRT (r = 0.43; 95% CI [0.19, 0.67]; p< 0.001, r = 0.36, 95% CI [0.12, 0.59]; p= 0.003, respectively) and with centre and inner LDI (r = 0.37; 95% CI [0.05, 0.69]; p= 0.024, r = 0.41; 95% CI [0.08, 0.74]; p= 0.015, respectively). Conclusion: Non-invasive imaging can detect differences between affected and non-affected skin in JLS and may help to differentiate between activity (thicker, less well perfused skin) and damage (thinner, highly perfused skin).