High-yield overview
Episodic Digital Vasospasm - Is It Primary or Secondary?
White-Blue-RedTriphasic colour change
PrimaryBenign, no underlying disease
SecondarySystemic sclerosis the main cause
CCBFirst-line drug (nifedipine)
Primary vs secondary Raynaud's
Primary (Raynaud's disease)
PatternNo underlying cause; younger women, symmetrical, mild, NO tissue loss, NORMAL nailfold capillaries, negative ANA/normal inflammatory markers. Benign.
Treatment
Secondary (Raynaud's phenomenon)
PatternUnderlying cause - CONNECTIVE TISSUE DISEASE (systemic sclerosis most common, also SLE/MCTD/dermatomyositis), occupational (hand-arm VIBRATION), hypothenar hammer syndrome, drugs, haematologic. Older onset, asymmetric, severe, digital ULCERS, abnormal capillaroscopy, positive autoantibodies.
Treatment
Critical Must-Knows
- Raynaud's phenomenon is episodic VASOSPASM of the digital arteries triggered by COLD or EMOTIONAL stress, producing the classic TRIPHASIC colour change: WHITE (pallor from ischaemia) -> BLUE (cyanosis from deoxygenation) -> RED (rubor from reperfusion hyperaemia), with accompanying numbness, pain and tingling.
- The cardinal task is to separate PRIMARY Raynaud's (Raynaud's disease - no underlying cause) from SECONDARY Raynaud's (phenomenon - with an underlying cause). Primary disease is more common, affects younger WOMEN, is symmetrical and mild with no tissue loss, normal nailfold capillaries and negative autoimmune workup, and is benign.
- SECONDARY Raynaud's most often reflects a CONNECTIVE TISSUE DISEASE - SYSTEMIC SCLEROSIS is the commonest cause - but also SLE, mixed connective tissue disease and dermatomyositis; non-rheumatic causes include occupational hand-arm VIBRATION (vibration white finger), HYPOTHENAR HAMMER SYNDROME, drugs (beta-blockers, ergot, chemotherapy, stimulants), and haematologic/vascular disease.
- RED FLAGS for a secondary cause are: onset after age ~40, MALE sex, ASYMMETRIC attacks, SEVERE episodes with digital ULCERS/pitting/tissue loss, ABNORMAL nailfold capillaroscopy and POSITIVE autoantibodies or systemic features - these warrant rheumatology referral and a search for the cause.
- WORKUP: history (drugs, vibration/occupation, systemic symptoms) and examination (digital ulcers, sclerodactyly, telangiectasia, calcinosis), NAILFOLD CAPILLAROSCOPY (giant capillaries and reduced capillary density define a 'scleroderma pattern'), and autoantibodies (ANA, anti-centromere, anti-Scl-70) with inflammatory markers; an Allen's test and vascular assessment if a localised arterial cause is suspected.
- MANAGEMENT is a ladder: first CONSERVATIVE - keep the hands and body WARM (gloves, hand warmers), STOP SMOKING, avoid vasoconstrictors (non-selective beta-blockers, stimulants) and treat stress; first-line DRUG therapy is a dihydropyridine CALCIUM-CHANNEL BLOCKER (nifedipine/amlodipine), with PDE5 inhibitors (sildenafil), topical nitrates, ARBs or alpha-blockers as alternatives; for severe digital ischaemia/ULCERS (especially in systemic sclerosis) IV PROSTACYCLIN (iloprost) and endothelin antagonists (bosentan to prevent new ulcers) are used, and SURGERY (digital sympathectomy, botulinum toxin, or treating an underlying hypothenar hammer/embolic source) is reserved for refractory critical ischaemia.
Clinical Pearls
- “Triphasic colour change: WHITE (ischaemia) -> BLUE (cyanosis) -> RED (reperfusion).
- “Primary = benign (young woman, symmetric, normal capillaroscopy, ANA-negative); Secondary = systemic sclerosis #1 (red flags: >40, male, asymmetric, ulcers, abnormal capillaroscopy, +autoantibodies).
- “Ladder: warmth/stop smoking/avoid beta-blockers -> CCB (nifedipine) first-line -> PDE5/prostacyclin/bosentan for ulcers -> surgery (digital sympathectomy) for refractory ischaemia. Exclude hypothenar hammer syndrome.
Primary or Secondary? - It Changes Everything
Primary (benign)
Young woman, symmetric, mild, no tissue loss, normal nailfold capillaries, negative ANA/normal markers. Reassure + conservative care.
Secondary (find the cause)
Onset >40/male, asymmetric, severe with digital ulcers, abnormal capillaroscopy, positive autoantibodies - think systemic sclerosis; refer to rheumatology.
Presentation & the Triphasic Colour Change
White, Blue, Red
An attack is provoked by cold or emotion and classically passes through three colours: WHITE (pallor) as the digital arteries vasospasm and the finger becomes ischaemic; BLUE (cyanosis) as the static blood deoxygenates; and RED (rubor) as vasospasm resolves and reactive hyperaemia floods the finger. The colour change is usually well demarcated, affects the fingers (sparing the thumb in some), and is accompanied by numbness, tingling and pain, then throbbing on rewarming. Not every patient shows all three phases, but the sharply demarcated pallor of digital ischaemia is the hallmark.
Primary vs Secondary & Workup
Find (or Exclude) an Underlying Cause
Primary Raynaud's is common, benign and needs no extensive workup if the picture is typical (young woman, symmetric, mild, normal examination). Secondary Raynaud's must be actively sought, because it can herald a serious systemic disease. Red flags: onset after ~40, male sex, asymmetry, severe attacks with digital ulcers/pitting/gangrene, abnormal nailfold capillaries and positive autoantibodies. Causes include:
- Connective tissue disease - systemic sclerosis (commonest), SLE, MCTD, dermatomyositis/polymyositis.
- Occupational/vascular - hand-arm vibration syndrome (vibration white finger), hypothenar hammer syndrome, thoracic outlet syndrome, atherosclerosis, emboli.
- Drugs - beta-blockers, ergot, chemotherapy, sympathomimetics/stimulants.
- Haematologic - cryoglobulinaemia, polycythaemia. Investigations: examine for sclerodactyly/telangiectasia/calcinosis/ulcers; nailfold capillaroscopy (giant capillaries + reduced capillary density = scleroderma pattern); ANA/ENA (anti-centromere, anti-Scl-70) and inflammatory markers; Allen's test/vascular imaging if a localised arterial cause is suspected.
Management
The Treatment Ladder
- Conservative (all patients): keep the whole body and hands WARM (gloves, hand/pocket warmers, layer clothing), STOP SMOKING, manage stress, and avoid vasoconstrictors - non-selective beta-blockers, ergotamine, sympathomimetics and stimulants.
- First-line drug: a dihydropyridine CALCIUM-CHANNEL BLOCKER (nifedipine or amlodipine) reduces attack frequency and severity - the most widely used agent.
- Second-line/alternatives: PDE5 inhibitors (sildenafil), topical nitrates, ARBs (losartan), alpha-blockers (prazosin), or SSRIs (fluoxetine).
- Severe disease / digital ulcers (especially systemic sclerosis): IV prostacyclin (iloprost) for critical ischaemia/active ulcers, and the endothelin-receptor antagonist bosentan to reduce new digital ulcers.
- Refractory critical ischaemia: surgery - peripheral/digital (periarterial) sympathectomy, botulinum toxin injection, and treating any underlying arterial lesion (e.g. hypothenar hammer syndrome, embolic source); debride/amputate established gangrene.
The Hand Surgeon's Role - Don't Miss a Local Arterial Cause
When Raynaud's is unilateral, affects only certain digits, or presents with digital ischaemia/ulcers, exclude a local arterial cause - especially HYPOTHENAR HAMMER SYNDROME (ulnar artery aneurysm/ thrombosis at Guyon's canal from repetitive palmar trauma) and embolic sources - with an Allen's test and vascular imaging (duplex/angiography). These are surgically treatable and are missed if every case is labelled 'Raynaud's'. (See our Hypothenar Hammer Syndrome and Ulnar Tunnel topics.)
Evidence & Key Studies
Evidence
Sociodemographic and pharmacological characteristics of patients with primary and secondary Raynaud's phenomenon
Valladales-Restrepo LF, Henao-Martinez M, Velasquez-Quimara S, et al. • Vascular Diseases (2025)
Key Findings:
- Of 567 patients (mean age 51.9 years, 82.5% women), 58.7% had primary and 41.3% secondary Raynaud's phenomenon.
- The most frequent secondary cause was systemic sclerosis (36.8%); calcium-channel blockers were the most used drugs (45.7%).
- 9.2% of patients were taking drugs that can worsen Raynaud's (mostly non-selective beta-blockers) - a reminder to review the drug history.
Evidence
Evaluation of algorithms to identify the scleroderma pattern in nailfold videocapillaroscopy
Shinzato A, Sekiyama JY, Kayser C • Clinical and Experimental Rheumatology (2025)
Key Findings:
- Nailfold videocapillaroscopy is well established in evaluating Raynaud's phenomenon and systemic sclerosis.
- Reduced capillary density (<=8 capillaries/mm) best identified the scleroderma pattern (accuracy ~88%), and giant capillaries were highly specific (~98%).
- Combining giant capillaries with low density gave high accuracy (~91%) - supporting capillaroscopy to distinguish secondary (scleroderma-pattern) from primary Raynaud's.
Evidence Attribution
According to PubMed, the primary/secondary proportions, systemic sclerosis as the main secondary cause, the predominance of calcium-channel blockers and the risk of beta-blockers worsening Raynaud's come from the cited Valladales-Restrepo study, and the role of nailfold capillaroscopy (giant capillaries, reduced density) in identifying the scleroderma pattern from the cited Shinzato study. The triphasic colour change, red flags and treatment ladder are standard, well-established teaching. (See also our Systemic Sclerosis / Connective Tissue Disease and Hypothenar Hammer Syndrome topics.)
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
Viva scenarioStandard
Clinical prompt
“A patient describes their fingers going white then blue then red in the cold. How do you decide if this is primary or secondary Raynaud's, and why does it matter?”
Practical approach
The white-then-blue-then-red triphasic colour change is the classic description of Raynaud's phenomenon, episodic vasospasm of the digital arteries provoked by cold or emotion, giving pallor from ischaemia, cyanosis from deoxygenation, and rubor from reperfusion. My key task is to decide whether it is primary Raynaud's disease, which has no underlying cause and is benign, or secondary Raynaud's phenomenon, which has an underlying cause and may be serious. Primary disease typically affects younger women, is symmetrical and mild, causes no tissue loss, and has normal nailfold capillaries and a negative autoimmune workup. I would look for red flags of a secondary cause: onset after about forty, male sex, asymmetric attacks, severe episodes with digital ulcers, pitting or gangrene, abnormal nailfold capillaroscopy, and positive autoantibodies or systemic features. The commonest secondary cause is a connective tissue disease, particularly systemic sclerosis, but I would also consider occupational vibration exposure, hypothenar hammer syndrome, drugs such as beta-blockers, and haematological causes. So I take a careful history including drugs and occupation, examine for sclerodactyly, telangiectasia, calcinosis and ulcers, perform nailfold capillaroscopy looking for giant capillaries and reduced capillary density that define a scleroderma pattern, and check ANA and specific antibodies with inflammatory markers. It matters because primary disease just needs reassurance and conservative care, whereas secondary Raynaud's can be the first sign of systemic sclerosis and needs rheumatology referral and treatment of the underlying disease, and unilateral or digit-specific ischaemia may have a surgically treatable arterial cause such as hypothenar hammer syndrome.
Key clinical points
Triphasic colour change = digital vasospasm (white->blue->red)
Primary: young woman, symmetric, mild, normal capillaroscopy, ANA-negative (benign)
Secondary red flags: >40/male, asymmetric, ulcers, abnormal capillaroscopy, +autoantibodies; systemic sclerosis #1
Workup: history/drugs, exam, nailfold capillaroscopy, ANA/ENA; exclude local arterial cause (HHS)
Common pitfalls
Missing systemic sclerosis behind 'just Raynaud's'
Not doing nailfold capillaroscopy/autoantibodies in red-flag cases
Overlooking a unilateral arterial cause (hypothenar hammer syndrome)
Further questions
“Commonest secondary cause? - Systemic sclerosis”
“What capillaroscopy findings suggest secondary disease? - Giant capillaries + reduced capillary density (scleroderma pattern)”
Viva scenarioStandard
Clinical prompt
“How would you manage a patient with troublesome Raynaud's, including one with digital ulcers from systemic sclerosis?”
Practical approach
I would manage Raynaud's as a ladder. For all patients I start with conservative measures: keeping the whole body and the hands warm with gloves and hand warmers, layering clothing, stopping smoking, managing stress, and avoiding vasoconstrictor drugs such as non-selective beta-blockers and stimulants, and I would review the drug history because some patients are inadvertently on agents that worsen it. The first-line drug is a dihydropyridine calcium-channel blocker such as nifedipine or amlodipine, which reduces the frequency and severity of attacks. If that is inadequate I would add or switch to alternatives such as a PDE5 inhibitor like sildenafil, topical nitrates, an angiotensin-receptor blocker, or an alpha-blocker. For severe disease, particularly digital ulcers in systemic sclerosis, I would escalate to intravenous prostacyclin such as iloprost for critical ischaemia and active ulcers, and use the endothelin-receptor antagonist bosentan to reduce the development of new digital ulcers, alongside good wound care and treating infection. For refractory critical ischaemia I would consider surgery - a digital or peripheral periarterial sympathectomy or botulinum toxin injection - and I would always exclude and treat a surgically correctable arterial cause such as hypothenar hammer syndrome or an embolic source; established gangrene may need debridement or amputation. Throughout, secondary Raynaud's is managed jointly with rheumatology treating the underlying disease.
Key clinical points
Conservative: warmth, stop smoking, avoid beta-blockers/stimulants, stress management
First-line: dihydropyridine CCB (nifedipine/amlodipine); then PDE5i/nitrates/ARB/alpha-blocker
Digital ulcers (systemic sclerosis): IV prostacyclin (iloprost) + bosentan to prevent new ulcers
Refractory ischaemia: digital sympathectomy / botulinum toxin; treat HHS/emboli; MDT with rheumatology
Common pitfalls
Leaving the patient on a beta-blocker
Not escalating to prostacyclin/bosentan for digital ulcers in scleroderma
Forgetting the surgically treatable arterial causes
Further questions
“First-line drug? - Dihydropyridine CCB (nifedipine)”
“Drug to prevent new digital ulcers in systemic sclerosis? - Bosentan (endothelin antagonist)”
Mnemonics & Memory Aids
Mnemonic
WBR
W
White - pallor (vasospasm/ischaemia)
B
Blue - cyanosis (deoxygenation)
R
Red - rubor (reperfusion hyperaemia)
Hook:Raynaud's runs White -> Blue -> Red (WBR).
Mnemonic
SECONDARY
S
Systemic sclerosis (commonest) + other CTD (SLE/MCTD)
E
Elderly/onset >40 (red flag)
C
Capillaroscopy abnormal (giant capillaries/dropout)
O
Occupational vibration (vibration white finger)
N
Nasty: ulcers/asymmetry/male (red flags)
D
Drugs (beta-blockers, ergot, stimulants)
A
Antibodies positive (ANA/anti-centromere/Scl-70)
R
Regional arterial cause (hypothenar hammer/emboli)
Y
Yield to rheumatology referral
Hook:SECONDARY lists the causes and red flags for secondary Raynaud's.
Exam day cheat sheet
Raynaud's Phenomenon - Exam Day Cheat Sheet
Presentation
- Episodic digital vasospasm triggered by cold/emotion
- Triphasic colour: WHITE (ischaemia) -> BLUE (cyanosis) -> RED (reperfusion)
- Numbness/pain; well-demarcated pallor
Primary vs secondary
- Primary: young woman, symmetric, mild, normal capillaroscopy, ANA-negative (benign)
- Secondary causes: systemic sclerosis (#1), SLE/MCTD, vibration, HHS, drugs, haematologic
- Red flags: >40/male, asymmetric, digital ulcers, abnormal capillaroscopy, +autoantibodies
Workup
- History (drugs/occupation), exam (sclerodactyly/telangiectasia/ulcers)
- Nailfold capillaroscopy (giant capillaries + reduced density = scleroderma pattern)
- ANA/ENA (anti-centromere, Scl-70) + markers; Allen's test/imaging if local cause
Management ladder
- Warmth, stop smoking, avoid beta-blockers/stimulants, stress management
- 1st-line: dihydropyridine CCB (nifedipine); then PDE5i/nitrates/ARB/alpha-blocker
- Digital ulcers (SSc): IV iloprost + bosentan; refractory: digital sympathectomy/botox; exclude HHS