Correlations between skin blood perfusion values and nailfold capillaroscopy scores in systemic sclerosis patients

To correlate blood perfusion (BP) values assessed by laser speckle contrast analysis (LASCA) in selected skin areas of hands and face with nailfold capillary damage scores in systemic sclerosis (SSc) patients.

Seventy SSc patients (mean SSc duration 6 ± 5 years) and 70 volunteer healthy subjects were enrolled after informed consent. LASCA was performed at different areas of the face (forehead, tip of nose, zygomas and perioral region) and at dorsal and volar regions of hands. Microvascular damage was assessed and scored by nailfold videocapillaroscopy (NVC) and the microangiopathy evolution score (MES) was calculated.

SSc patients showed a significantly lower BP than healthy subjects at fingertips, periungual areas and palm of hands (p<0.0001), but not at the level of face and dorsum of hands. A gradual decrease of BP at fingertips, periungual and palm areas, was found in SSc patients with progressive severity of NVC patterns of microangiopathy ("early", "active", or "late") (p<0.01). A negative correlation was observed between MES and BP values, as well as between loss of capillaries and BP, at the same areas (p<0.001 and p<0.01, respectively). Patients with diffuse cutaneous SSc (dcSSc) showed lower BP than those with limited cutaneous SSc (p<0.04).

LASCA detects a significant reduction of BP only in those areas usually affected by Raynaud's phenomenon (fingertips, periungual and palm areas), especially in dcSSc patients, and BP values significantly correlate with the nailfold capillaroscopy scores of microangiopathy.