Raynaud's Phenomenon

Raynaud's phenomenon is episodic, reversible vasospasm of the small digital arteries and arterioles. Cold exposure and emotional stress can trigger an exaggerated vasoconstrictor response, briefly reducing blood flow to the fingers, toes, or both. The classic color sequence is pallor, followed by cyanosis, followed by erythema as the digit rew warms. Pallor reflects markedly reduced inflow. Cyanosis develops when sluggish blood flow leaves more deoxygenated blood in the tissue. Redness during rewarming reflects reactive hyperemia. Not every patient shows all three colors, and an attack may last minutes to several hours. Numbness, tingling, burning, or pain can accompany the color change. The first clinical question is not simply, “Is this Raynaud's?” It is, “Is the vasospasm occurring in otherwise healthy digital vessels, or is it revealing systemic vascular disease?” Primary Raynaud's has no identifiable underlying illness and does not cause digital ulcers, pitting scars, gangrene, or autoamputation. Secondary Raynaud's is associated with another disorder—most notably systemic sclerosis and other connective tissue diseases—and may progress from reversible spasm to persistent ischemia and tissue loss.