Raynaud Phenomenon
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Direct answer
Raynaud phenomenon is episodic digital vasospasm triggered by cold or emotional stress, producing a sequence of white, blue and red colour changes in the fingers. It is primary when it occurs alone and secondary when linked to conditions such as systemic sclerosis, SLE or mixed connective tissue disease. Nailfold capillaroscopy is the most useful bedside step to distinguish the two.
What you must remember
- Triphasic colour change: White from arterial spasm, blue from deoxygenated stagnation, and red from reactive hyperaemia on rewarming.
- Primary Raynaud: Begins before about 30 years, is symmetrical, causes no tissue loss, and has normal nailfold capillaries with no specific antibodies.
- Secondary Raynaud: Later onset, asymmetry, digital ulcers or pitting scars suggest an underlying disease, most often systemic sclerosis.
- Nailfold capillaroscopy: Normal in primary disease, whereas giant capillaries, haemorrhages and avascular areas indicate a scleroderma pattern.
- Autoantibodies: Anticentromere antibody is linked with limited cutaneous systemic sclerosis and anti-Scl-70 with diffuse disease.
- Vasodilator therapy: Dihydropyridine calcium channel blockers such as nifedipine or amlodipine are first-line; non-selective beta-blockers are avoided and vasoconstrictive drugs are stopped where possible.
A reasoned approach: cold fingers in a young woman
Consider a 34-year-old woman with cold, painful fingers that turn white and then blue on winter mornings. History matters first: the age at onset, whether both hands are affected symmetrically, and whether ulcers or tissue loss have occurred. Examination looks for sclerodactyly, telangiectasia, tight skin and digital pitting, and nailfold capillaroscopy is performed at the bedside. A normal capillary pattern with no skin change and no tissue loss suggests primary Raynaud. The team then checks TSH and takes a drug history, including beta-blockers and ergot-containing migraine treatment. If capillaroscopy shows a scleroderma pattern or antibodies such as anticentromere or anti-Scl-70 are positive, rheumatology review is arranged to screen for systemic sclerosis. Primary disease is managed with cold avoidance, smoking cessation and a calcium channel blocker, while digital ulcers in secondary disease may need specialist-directed vasodilator therapy. New skin changes or tissue loss at follow-up signal that the diagnosis needs revisiting. Cold-weather protection and avoidance of vibrating tools are discussed, and smoking cessation support is offered, since nicotine intensifies vasospasm. Digital ulcers are dressed carefully and infection is treated promptly, because a small ulcer can progress to tissue loss.
Where the exam tries to catch you
The classic trap is treating Raynaud as a diagnosis rather than a phenomenon. It accompanies many conditions, so the question is always whether the features point to primary or secondary disease. Age at onset is the easiest clue: onset after about 30 to 40 years, especially with asymmetric involvement or ulceration, points away from primary disease. The triphasic colour sequence is characteristic of Raynaud, whereas persistent cyanosis without pallor suggests a fixed circulatory problem. Buerger disease, which affects distal arteries in young male smokers, is a differential worth remembering. Finally, beta-blockers are often considered for coexisting hypertension, but non-selective agents worsen Raynaud, and the examiner expects a calcium channel blocker as the alternative.
Frequently asked questions
What is the difference between primary and secondary Raynaud phenomenon?
Primary Raynaud phenomenon occurs without an underlying disease, usually begins before about 30 years, is symmetrical and causes no tissue loss. Secondary Raynaud phenomenon is linked to conditions such as systemic sclerosis, starts later, may be asymmetric and can cause digital ulcers.
Which test helps distinguish systemic sclerosis-related Raynaud from the primary form?
Nailfold capillaroscopy is the key bedside test: a normal capillary pattern favours primary Raynaud, while giant capillaries, haemorrhages and avascular areas suggest systemic sclerosis. Antinuclear and specific antibodies are then checked to refine the diagnosis.
Which drugs can precipitate or worsen Raynaud phenomenon?
Non-selective beta-blockers, ergot alkaloids and some chemotherapy agents such as bleomycin can precipitate or worsen Raynaud phenomenon. Vasoconstrictive drugs should be reviewed and replaced where possible, and stopping the offending drug often improves symptoms.
Which drug class is first-line for vasodilator therapy in Raynaud phenomenon?
Dihydropyridine calcium channel blockers such as nifedipine or amlodipine are the first-line vasodilators for Raynaud phenomenon. Topical nitrates and phosphodiesterase-5 inhibitors are considered when calcium channel blockers are not tolerated or are insufficient.