Raynaud's phenomenon in arterial obstructive disease of the hand demonstrated by locally provoked cooling.

Finger systolic blood pressure (FSP) was measured by cuff technique before and after local cooling in three groups of patients (Raynaud's disease (7), subclavian stenoses, (5), thrombo-angiitis obliterans (15)), and in 15 normals. The response to finger cooling registered as a decrease in FSP indicates an increase of digital arterial tone. In all three groups, digital arterial tone increased more than in normals during finger cooling. Patients with Raynaud's disease showed a pathological increase in arterial tone at 23.5 degrees C with closure of the digital arteries at a mean temperature of 18.5 degrees C. The temperature eliciting these phenomena in patients with thrombo-angiitis obliterans was about 7 degrees C lower (16.5 and 11.0 degrees C, respectively). Accordingly, cold sensitivity and Raynaud's phenomena in the two groups may have a different pathophysiological mechanism, namely a pathological arterial tone in Raynaud's disease vs. a normal arterial tone in obliterative diseases acting on a narrow vessel.