Which capillary microscopy finding differentiates Raynaud phenomenon from Raynaud disease?

Which capillary microscopy finding differentiates Raynaud phenomenon from Raynaud disease?

• A. Preserved capillary loops
• B. Absent capillaries
• C. Enlarged capillary loops
• D. Decreased or distorted capillary loops

Answer: (D)

Capillary microscopy (nailfold capillaroscopy) distinguishes primary from secondary Raynaud by the microvascular pattern. In the primary form, the capillaries look normal with preserved loop architecture, normal density, and no hemorrhages. When Raynaud’s phenomenon is secondary to an underlying connective tissue disease, the capillaries show clear abnormalities: dropouts with decreased capillary density, and loops that become distorted or irregular. These changes reflect underlying vascular involvement and reliably point to a secondary process rather than the primary Raynaud’s. Thus, finding decreased or distorted capillary loops is the hallmark that differentiates Raynaud phenomenon (secondary) from Raynaud disease (primary).

Capillary microscopy (nailfold capillaroscopy) distinguishes primary from secondary Raynaud by the microvascular pattern. In the primary form, the capillaries look normal with preserved loop architecture, normal density, and no hemorrhages. When Raynaud’s phenomenon is secondary to an underlying connective tissue disease, the capillaries show clear abnormalities: dropouts with decreased capillary density, and loops that become distorted or irregular. These changes reflect underlying vascular involvement and reliably point to a secondary process rather than the primary Raynaud’s.

Thus, finding decreased or distorted capillary loops is the hallmark that differentiates Raynaud phenomenon (secondary) from Raynaud disease (primary).