Raynaud's syndrome description includes which of the following?

• A. Cyanosis
• B. All three
• C. Ischemia of the fingers (and occasionally other acral regions)
• D. Hyperemia

Answer: (B)

Raynaud's phenomenon is defined by episodic vasospasm of the small vessels in the digits, producing a distinctive color sequence and temporary ischemia. At the start, reduced blood flow causes pallor as the area becomes white (ischemia). If the vasospasm continues, the digits turn blue due to deoxygenated blood (cyanosis). As the attack resolves, blood flow returns and the digits redden with hyperemia, often with warmth. Because these phases reflect the full cycle of ischemia, cyanosis, and subsequent reperfusion, describing all three aspects best fits Raynaud's phenomenon. Describing only one phase (pallor, cyanosis, or hyperemia) would miss the others that typically occur in the same episode, even though the involvement can extend to other acral regions.