Objectives: To assess by Laser Doppler perfusion imaging (LDPI) skin blood perfusion of hands in patients with SSc and primary RP (PRP) at baseline and after cold stimulation (CS). In SSc patients, the associations between skin perfusion and nailfold video capillaroscopy (NVC) patterns were also evaluated.
Methods: Forty patients with SSc, 38 patients with PRP and 32 healthy controls were recruited. Skin blood flow of the hands was detected by Lisca Laser Doppler Perfusion Imager at baseline and after CS. Further laser Doppler scanning was performed for each hand at 0 (T(1)), 3 (T(2)), 7 (T(3)) and 15 min (T(4)).
Results: Baseline mean perfusion is significantly (P < 0.000 l) lower in SSc patients than in healthy controls. In SSc patients, mean perfusion is reduced after CS (P < 0.0001) and skin flow recovery (significant difference between T(0) and T(4), P < 0.0001) is incomplete. In SSc patients with low vascular damage (early and active capillaroscopic groups), the abnormal microvascular response to CS involves only the digits, while the perfusion of hands dorsum is normal. With the progression of vascular damage (late capillaroscopic groups), the abnormal microvascular response to CS also appears in the hand dorsum skin. In PRP patients, baseline hand perfusion is very low and the skin flow recovery after CS is absent (P < 0.05).
Conclusion: In early SSc, the thermoregulation of finger skin is impaired, but only in advanced stages of microangiopathy does the skin of the hand dorsum show a vasomotor control failure.