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

Objectives: To evaluate whether in juvenile localized 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: A total of 25 children with JLS were recruited into a prospective study and a single 'target' lesion was 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 (1 cm from the edge of the lesion 'outer' and contralateral non-affected side) at four visits at 3 month intervals. Results: Differences between affected and non-affected skin were detected with all four 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 1/4 0.32 (95% CI 0.02, 0.61), P 1/4 0.036] and negatively correlated with centre LDI [r 1/4 (y) over double dot0.26 (95% CI (y) over double dot0.49, (y) over double dot0.04), P 1/4 0.022]. Lesion skin damage was positively correlated with centre and inner IRT [r 1/4 0.43 (95% CI 0.19, 0.67), P < 0.001 and r 1/4 0.36 (95% CI 0.12, 0.59), P 1/4 0.003, respectively] and with centre and inner LDI [r 1/4 0.37 (95% CI 0.05, 0.69), P 1/4 0.024 and r 1/4 0.41 (95% CI 0.08, 0.74), P 1/4 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).