Which description best fits primary Raynaud disease?

Primary Raynaud disease primarily manifests as episodic vasospasms of the small blood vessels, particularly in the fingers and toes, in response to cold temperatures or emotional stress. This condition is characterized by a classic triphasic color change in the digits: initially pallor (white) due to vasoconstriction, followed by cyanosis (bluish discoloration) as the blood flow is reduced, and often a return to normal redness when circulation improves. The bluish discoloration noted in the correct answer is a key clinical feature associated with Raynaud's phenomenon.

In contrast, other options describe symptoms and conditions that do not relate to Raynaud disease. For instance, pain and burning sensations in the legs that are relieved by elevation are indicative of peripheral vascular issues, such as venous insufficiency, rather than Raynaud's. Numbness and tingling in the feet are more consistent with diabetic neuropathy, particularly in patients with type 2 diabetes, and exercise-induced claudication is typically associated with peripheral arterial disease, particularly in smokers. These symptoms are distinct and stem from different underlying pathophysiological mechanisms.