Raynaud's Phenomenon

🔍 When to Suspect

Patient presents with episodes of well-demarcated, triphasic colour changes in the fingers or toes (white, then blue, then red), typically triggered by cold or stress

From the full topic in The Ocean Library: Raynaud's Phenomenon

🧭 When to suspect

Raynaud's phenomenon (RP) is episodic, reversible vasospasm of the digital arteries and arterioles, producing sharply demarcated colour change in the fingers and toes – classically triphasic: pallor (white, ischaemia), then cyanosis (blue, deoxygenation), then rubor (red, reperfusion) – although not every attack runs the full sequence. Attacks are provoked by cold or emotional stress, with accompanying numbness, tingling or pain that is most marked on rewarming. It is common, affecting around 1 in 10 people in the UK.

The single most important clinical task is to separate primary Raynaud's (idiopathic and benign) from secondary Raynaud's (a marker of an underlying disorder, most importantly connective tissue disease). Suspect the secondary form whenever onset is late, attacks are asymmetrical, or there is any tissue damage.

Feature	Primary Raynaud's	Secondary Raynaud's
Typical onset	Adolescence to 20s (under 30)	Over 30 – especially over 40, and in men
Sex	Up to 9× more common in women	Either sex
Symmetry	Symmetrical (both hands)	May be asymmetrical
Thumb	Usually spared	May be involved
Tissue damage	None (no ulcers or pitting scars)	Digital pitting, ulcers or gangrene possible
Nailfold capillaries	Normal	Dilated loops or capillary dropout
Antinuclear antibody	Negative	Often positive (with specific antibodies)
Underlying cause	None; family history common	Connective tissue disease, drugs, occupational

Causes of secondary Raynaud's group usefully into: connective tissue disease – systemic sclerosis (the commonest and most important), systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), Sjögren's, dermatomyositis and rheumatoid arthritis (RA); drugs – beta-blockers, sympathomimetic decongestants, ergot and triptan migraine therapies, and certain chemotherapy agents; occupational – hand-arm vibration syndrome (HAVS) from vibrating tools; haematological – cryoglobulinaemia, polycythaemia and paraproteinaemia; and endocrine – hypothyroidism. Smoking aggravates every form.

Source: British Society for Rheumatology

---