Raynaud's phenomenon. An update.

Abstract

The pathogenesis of primary Raynaud's phenomenon remains an enigma. Most evidence favors a local abnormality in the digital arteries as opposed to an increased activity of the sympathetic nervous system. The local fault may involve the a^-adrenergic receptors, which are most important in reflex sympathetic vasoconstriction. Cooling blood vessels increase the sensitivity of o>2-adrenergic receptors, increased levels of a^-adrenergic receptors are present in primary Raynaud's disease, and patients show an increased sensitivity to a^-adrenergic receptor agonists on finger blood flow. Serotonin has also been implicated, but the evidence is not compelling. In secondary Raynaud's phenomenon, vasospastic attacks can often be explained by a low arterial distending pressure, a thickened vessel wall, or absence of /J-adrenergic receptor activity. Diagnosis of primary Raynaud's disease relies on a typical history and normal physical examination, laboratory studies, and nailfold capillaroscopy. Finger systolic blood pressures during local cooling with ischemia may be helpful to document vasospastic attacks but does not distinguish primary from secondary Raynaud's phenomenon. The treatment of Raynaud's phenomenon is usually conservative. Pavlovian conditioning or biofeedback may be beneficial. When drug therapy is necessary, the calcium channel entry blocker nifedipine or sympatholytic agents have been shown to decrease the frequency and duration of vasospastic attacks in about two thirds of patients, although subjective improvement does not usually correlate with objective testing. Direct-acting vasodilators have not been shown to be of definite benefit New therapies include prostaglandins, captopril, and the serotonergic antagonist ketanserin. Surgical sympathectomy has not been beneficial. (Hypertension 1991;17:593-602)

Digital Thermography of the Fingers and Toes in Raynaud's Phenomenon

“…Skin temperature differences between the center of palm and the coolest finger and between the center of the foot dorsum and the first toe was significantly bigger in RP patients than in controls, irrespective of RP symptom involving either hands or feet. RP is characterized by recurrent episodes of discoloration affecting the fingers and toes (10). According to a study of systemic sclerosis by La Montagna et al about 90% of patients were presented with features of RP in the feet (11) in contrast to 44% of the patients in our study.…”

Lack of habituation of the pattern of cardiovascular response evoked by sound in subjects with primary Raynaud’s disease

“…Several decades later, Thomas Lewis suggested that the vasospasm was caused by some factor that is local to the blood vessels [2]. Current thinking often combines these two hypotheses suggesting that vasospasm occurs in those people in whom neurally or hormonally mediated vasoconstriction is potentiated by the action of a locally released substance or substances (see [1,3]). Rather surprisingly, the idea that vasospasm can be evoked by emotional stress has not been explored.…”

The Handheld Dermatoscope as a Nail-Fold Capillaroscopic Instrument

“…3 The presence of these abnormalities may aid in early diagnosis of these disorders and in the differential diagnosis of primary Raynaud phenomenon (RP) from RP due to scleroderma and MCTD. 2,3,[6][7][8][9] The instruments used to observe capillaries in the living skin have ranged from a magnifying glass to microscopes of various designs and magnifying power. 2,4,7,10 A total magnification of ϫ12 to ϫ14 offers a wide field of observation and a perception of depth, the best conditions for evaluating the overall pattern of the capillary bed, both normal and abnormal.…”