Investigations

Routine blood tests are not carried out in primary Raynaud’s phenomenon (1).

A small group of investigations are helpful in patients with a clinical suspicion of secondary Raynaud’s phenomenon:

• full blood count and ESR
• presence of anaemia and lymphopenia, may suggest an underlying autoimmune disease;
• immunology test for antinuclear antibodies (ANA), anti-Ro (SS-A), and anti-La (SS-B) etc
• examination of nailfold capillaries:
• capillaroscopy is better since ophthalmoscopy (20× magnification, dermatoscope 10× magnification) can miss capillary changes
• but the gold standard method is videocapillaroscopy (200× magnification, or a biomicroscope)
• shows abnormal morphological patterns, e.g. dilatation, haemorrhages, loss of capillaries, angiogenesis etc (1)
• chest X-ray - in patients with unilateral signs to look for a cervical rib compressing the bronchial and cephalic vascular branches
• renal and liver function tests
• TFTs
• cryoglobulin estimation
• urinalysis
• hand X-ray (1,2,3)

Specialist investigations carried out in secondary care include:

• infrared thermography
• laser doppler flowmetry
• portable radiometry
• digital plethymography (1)

Note:

• laboratory tests must be used in conjunction with clinical features (1).

Reference:

• (1) Raynaud’s & Scleroderma association. Raynaud’s & Scleroderma - An update for GP’s
• (2) Wigley FM. Raynaud’s phenomenon. NEJM 2002;347:1001-1008
• (3) Goundry B, Bell L, Langtree M, Moorthy A. Diagnosis and management of Raynaud's phenomenon. BMJ. 2012;344:e289