Laser Doppler skin perfusion pressure in the assessment of Raynaud's phenomenon

Objectives. In the assessment of Raynaud's phenomenon, objective evaluation of digital microcirculatory flow is important, and so we investigated whether the measurement of laser Doppler skin perfusion pressure could be of use. Materials and methods. Ten fingers of five patients with secondary Raynaud's phenomenon due to systemic sclerosis, 22 fingers of 11 patients with primary Raynaud's phenomenon and 10 fingers of five control patients were examined. Skin perfusion pressure was measured on the third finger of both hands at rest, and then again 3 min after local cold exposure. Results. Laser Doppler skin perfusion pressure at rest in patients with secondary Raynaud's phenomenon was significantly lower than that in patients with primary Raynaud's phenomenon and the control patients (p < 0.05). Skin perfusion pressure decreased significantly in both patient groups upon local cold exposure (p = 0.005). There were significant differences in perfusion pressure after cold exposure among both groups (p < 0.05). Conclusions. The low skin perfusion pressure at rest in patients with secondary Raynaud's phenomenon suggested the presence of obstructive arterial lesions. The marked pressure decrease in all Raynaud's patients after local cold exposure might be due to vasospasm of the microvasculature in the digits. These results indicate that the measurement of laser Doppler skin perfusion pressure is valuable in the diagnosis of Raynaud's phenomenon.