Capillaroscopy in Raynaud's phenomenon

Raynaud's shows as colour changes in the fingers (white–blue–red) with cold or stress, or for no obvious reason. The key is to distinguish the primary form from the secondary form.

Relevant diagnoses:

Primary Raynaud's (often a normal finding) versus secondary Raynaud's (SSc spectrum, MCTD, SLE).

What is seen (findings in brief)

• Primary: regular arrangement, normal density, no megacapillaries or avascular areas.
• Secondary: megacapillaries, microhaemorrhages, capillary rarefaction/avascular areas.

How often to have a check-up

• Normal findings: 12–24 months
• Abnormal findings or ANA+: 6–12 months (earlier referral to a rheumatologist)

Summary

Capillaroscopy is the ‘gold standard’ for distinguishing primary from secondary Raynaud's.