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Raynaud's Phenomenon — episodic digital ischaemia UK primary care pathway for diagnosing and managing colour changes in fingers/toes triggered by cold or stress
Progress 0 / 9
The full reasoning pathway — distinguish benign primary Raynaud from secondary Raynaud (esp. with connective tissue disease), which needs investigation and can cause digital ischaemia. Treat, modify triggers, and safety-net.StartDecisionInvestigateActionReferStop / Admit
PresentationRaynaud phenomenon
Episodic colour change (white→blue→red) of digits with cold/stress. Age of onset, symmetry, digital ulcers, systemic features.
Step 1 · Safety — ischaemia / secondary diseaseCritical ischaemia or secondary disease?
Digital ulceration/necrosis (critical ischaemia) · onset >30, asymmetric, severe, with CTD features (sclerodactyly, abnormal nailfold capillaries, positive ANA).
YES
Stop · EscalateUrgent / investigate
Critical digital ischaemia → urgent vascular/rheumatology. Secondary features → autoimmune work-up.
NO
AssessBy pattern
History + examination localise the cause.
Step 3 · common causes
Primary Raynaud
Commonest
Young, symmetrical, no ulcers, normal ANA; keep warm, stop smoking, nifedipine if severe.
Secondary — CTD
Investigate
Scleroderma, SLE, mixed CTD; ANA, ENA, nailfold capillaroscopy → rheumatology.
Other secondary
Various
Drugs (beta-blockers), vibration injury, hypothyroidism, hyperviscosity.
ReferEscalation
Urgent critical digital ischaemia. Rheumatology suspected secondary Raynaud / connective tissue disease; manage primary with warmth + nifedipine.
Step 8 · lifestyle & trigger control
Step 8 · Lifestyle & trigger controlFirst-line for primary Raynaud
Keep warm — gloves/hand warmers, warm core and extremities, avoid sudden cold · stop smoking (vasoconstriction) · reduce caffeine · manage stress · review vasoconstrictor drugs (beta-blockers, decongestants, triptans, stimulants). For occupational vibration exposure, modify the task. Add nifedipine if attacks are frequent/severe despite measures.
Step 9 · monitoring & safety-net
Step 9 · Monitoring & safety-netReview & when to escalate
Review symptom control and re-examine for evolving CTD features (sclerodactyly, abnormal nailfold capillaries, new ANA positivity). Urgent for digital ulceration or necrosis (critical ischaemia → vascular/rheumatology). New late-onset, asymmetric or ulcerating Raynaud → reassess as secondary and refer.
⚠️ Late-onset, asymmetric or ulcerating Raynaud is secondary — check ANA and nailfold capillaries and refer rheumatology, as it may herald scleroderma or another connective tissue disease.
1
Safety

Red Flags — Screen for critical limb ischaemia and systemic disease

Exclude emergency vascular compromise and secondary causes requiring urgent specialist input.
Digital ulceration / gangrene Tissue loss, black necrotic areas, non-healing ulcers on fingertips → Same-day vascular surgery referral (critical limb ischaemia)
Asymmetric symptoms Unilateral, single digit involvement → 2-week vascular assessment (arterial occlusion, thoracic outlet syndrome)
Age <30 with severe attacks Especially if male, smoker → Urgent rheumatology (early systemic sclerosis, vasculitis)
Systemic symptoms Weight loss, fevers, arthralgia, rash, muscle weakness → 2-week rheumatology (connective tissue disease, vasculitis)
Digital pitting / sclerodactyly Tight shiny skin on fingers, loss of fingertip pulp → Urgent rheumatology (systemic sclerosis)
Rapidly progressive Increasing frequency/severity over weeks, new functional impairment → Routine rheumatology (secondary Raynaud's)
Severe pain / permanent colour change Persistent cyanosis, severe burning pain not relieved by warming → Same-day assessment (acute arterial occlusion)
Unilateral facial/ear symptoms One-sided face, ear, nose involvement → Routine ENT/neurology (temporal arteritis, neurological cause)

Critical limb ischaemia can lead to irreversible tissue damage within hours. Digital ulcers suggest severe underlying vasculopathy (systemic sclerosis carries 40% digital ulcer risk). Missing early systemic sclerosis delays disease-modifying treatment.

Asymmetric presentation is atypical for primary Raynaud's — suggests structural vascular abnormality (atherosclerosis, embolism, thoracic outlet compression). Single-digit involvement warrants imaging to exclude occlusion.

Young males with severe Raynaud's have higher risk of underlying connective tissue disease compared to typical primary Raynaud's demographic (young women with mild symptoms). Early rheumatology input prevents organ damage.

2
Diagnose

Confirmation — Take targeted history to establish diagnosis

Raynaud's is a clinical diagnosis. Confirm classic triphasic colour change and triggering factors.
Classic features
Triphasic colour change: White (pallor) → Blue (cyanosis) → Red (hyperaemia). Not all patients have all three phases. Episodes last 15-20 minutes.
Triggers
Cold exposure, emotional stress, vibration. Ask about occupational triggers (tools, typing).
Distribution
Bilateral, symmetrical. Fingers > toes. Thumbs often spared. Typically spares palm/sole.
Symptom diary
Ask patient to photograph attacks, record frequency, severity (0-10), duration, triggers, functional impact. Bring to next appointment.
Drug history
Beta-blockers, chemotherapy (bleomycin), ergot derivatives, clonidine, cocaine, amphetamines — all can cause/worsen Raynaud's.
Occupational
Vibrating tools (drill, chainsaw), repetitive trauma (typing, manual labour). May qualify for industrial injuries benefit.

Triphasic change is pathognomonic — reflects sequential arteriolar vasospasm (white), deoxygenated blood pooling (blue), and reperfusion (red). Some patients only report white or blue phase; red phase may be painful burning sensation.

Bilateral symmetry distinguishes primary from secondary (structural vascular lesions cause asymmetry). Thumb sparing occurs because digital arteries have less sympathetic innervation.

Photographic evidence is invaluable — many patients struggle to describe episodes. Confirms diagnosis when colour change witnessed. Symptom diary quantifies treatment response.

3
Diagnose

Classification — Primary vs Secondary Raynaud's

Distinguish primary (benign, idiopathic) from secondary (underlying disease) Raynaud's.
Primary Raynaud's
Criteria: Age onset <30 years, bilateral symmetrical, no digital tissue damage, normal nailfold capillaries, negative ANA, no systemic symptoms. Prevalence: 3-5% population, 90% of all Raynaud's cases. Benign prognosis
Secondary Raynaud's
Criteria: Age onset >30 years, asymmetric, digital ulcers/scars, abnormal nailfold capillaries, positive autoantibodies, systemic symptoms. Causes: Systemic sclerosis (most common), SLE, rheumatoid arthritis, Sjögren's, mixed connective tissue disease, vasculitis. Requires investigation
Drug-induced
Beta-blockers, chemotherapy (cisplatin, bleomycin), interferon, clonidine, ergotamine. Action: Review medication, consider alternatives. Symptoms may resolve 2-4 weeks post-cessation.
Occupational
Hand-arm vibration syndrome (HAVS). Requires >5 years vibration tool use. Action: HSE notification, refer occupational health, advise on compensation claims.
Other causes
Hypothyroidism, carpal tunnel syndrome, thoracic outlet syndrome, cryoglobulinaemia, hepatitis C, haematological (polycythaemia, thrombocytosis).

Age at onset is the strongest predictor: <30 years = 95% primary, >40 years = 50% secondary. Primary Raynaud's rarely develops after age 40.

Secondary Raynaud's carries significant morbidity — 30% of systemic sclerosis patients develop digital ulcers, 10% require amputation. Early rheumatology input enables disease-modifying treatment (methotrexate, mycophenolate) before irreversible fibrosis.

Connective tissue disease screening is cost-effective in new-onset Raynaud's >30 years. Positive ANA has 95% sensitivity for systemic sclerosis (though only 30% specificity). Abnormal nailfold capillaries predict progression to definite CTD in 80% at 5 years.

4
Diagnose

Examination — Assess for vascular and systemic disease

Focus on digital perfusion, tissue damage, and signs of underlying connective tissue disease.
Vital signs
BP both arms (>20 mmHg difference suggests subclavian stenosis). Radial pulse symmetry. Temperature.
Hands/feet
Look for: Digital ulcers, pitting scars, gangrene, calcinosis, sclerodactyly (tight shiny skin), nail fold changes. Significance: Tissue damage = secondary Raynaud's requiring rheumatology referral.
Nailfold capillaries
Use dermatoscope or ophthalmoscope (10-40x magnification). Normal: Regular parallel loops. Abnormal: Dilated loops, dropout (avascular areas), haemorrhages. Abnormal = refer rheumatology
Vascular exam
Allen's test (ulnar/radial artery patency), brachial/radial/ulnar pulses, capillary refill time (<2 seconds normal), Buerger's test (pallor on elevation). Asymmetry → vascular imaging.
Skin
Telangiectasia (face, hands — systemic sclerosis), malar rash (SLE), digital infarcts, livedo reticularis, calcinosis cutis.
Systemic signs
Lung crackles (interstitial lung disease), weak proximal muscles (myositis), dry eyes/mouth (Sjögren's), joint swelling (inflammatory arthritis). Present = urgent rheumatology
Neurological
Carpal tunnel signs (Tinel's, Phalen's) — can coexist with or mimic Raynaud's. Thoracic outlet tests (Adson's, Wright's).

Nailfold capillaroscopy is the single best bedside predictor of secondary Raynaud's. Abnormal capillaries have 92% sensitivity for systemic sclerosis. Normal capillaries virtually exclude significant CTD (99% negative predictive value).

Digital ulcers are not just a sign of severity — they're a treatment trigger. Presence of ulceration mandates phosphodiesterase-5 inhibitor (sildenafil) or endothelin receptor antagonist (bosentan) to prevent recurrence and amputation.

Allen's test abnormality (incomplete palmar arch) occurs in 5% of population but increases digital ischaemia risk in Raynaud's patients. Positive test warrants referral for vascular imaging.

5
Diagnose

Investigations — Screen for secondary causes

Investigate ALL new Raynaud's >30 years or any red flags. Do NOT investigate typical primary Raynaud's in young women.
Primary care bloods
FBC (anaemia in CTD, polycythaemia/thrombocytosis), ESR/CRP (inflammatory disease), ANA (connective tissue disease screen), TFTs (hypothyroidism), Protein electrophoresis (cryoglobulinaemia if indicated). Do if age >30 or red flags
ANA interpretation
Positive (≥1:80): Refer rheumatology for further autoantibody panel (anti-Scl70, anti-centromere, anti-RNP). Negative: Does NOT exclude CTD (15% systemic sclerosis are ANA-negative). Clinical suspicion overrides negative ANA.
Specialist bloods
Rheumatology will request: ENA panel (anti-Scl70 = diffuse SSc, anti-centromere = limited SSc), Anti-CCP/RF (RA), Cryoglobulins, Complement C3/C4 (SLE), ANCA (vasculitis). Do NOT order in primary care
Imaging — when needed
Chest X-ray: If lung symptoms (ILD in SSc). Doppler USS arterial: If asymmetric, weak pulses, or severe unilateral disease (atherosclerosis, thoracic outlet). NOT routine in bilateral symmetrical Raynaud's.
Do NOT investigate
Young women (<30 years) with bilateral, symmetrical, mild symptoms, no systemic features, normal examination. Diagnosis: Primary Raynaud's. Action: Reassure, lifestyle advice, review if worsening.

ANA screening has 93% sensitivity for systemic sclerosis but only 50% specificity (many false positives in healthy population, especially older adults). Titre matters: 1:160 or higher is more significant. Positive ANA requires clinical correlation — not all positive ANAs have CTD.

Overinvestigation harms patients: Investigating low-risk primary Raynaud's generates false-positive autoantibodies, causing anxiety and unnecessary rheumatology referrals. Number-needed-to-test to find one CTD in <30-year-old women = 250. Clinical assessment is more powerful than blanket serology.

Doppler USS detects structural arterial disease (stenosis, occlusion, aneurysm) but is normal in functional vasospasm. Reserve for atypical presentations suggesting atherosclerosis or thoracic outlet syndrome.

6
Refer

Referral Criteria — When to escalate

Refer secondary Raynaud's, severe primary Raynaud's, or diagnostic uncertainty.
Same-day
Digital gangrene, severe ulceration → Vascular surgery (acute critical limb ischaemia). Severe pain, permanent colour change → Medical on-call (acute arterial occlusion).
2-week urgent
Systemic symptoms (weight loss, fever, muscle weakness, rash) → Rheumatology. Digital pitting scars, sclerodactyly → Rheumatology (systemic sclerosis). Positive ANA with clinical features → Rheumatology.
Routine rheumatology
Age onset >40 years. Abnormal nailfold capillaries. Rapidly progressive symptoms (frequency/severity increasing over weeks). Refractory to lifestyle + nifedipine. Functional impairment (unable to work, daily activities limited).
Vascular surgery
Asymmetric symptoms, unilateral. Absent pulses, positive Allen's test. Occupational (HAVS) if severe and persistent despite trigger avoidance.
Primary care
Primary Raynaud's criteria met: Age <30, bilateral symmetrical, mild symptoms, normal exam, negative bloods (if done). Action: Lifestyle advice, trial nifedipine if moderate-severe, annual review.

Early rheumatology referral in secondary Raynaud's prevents irreversible complications. Systemic sclerosis patients benefit from immunosuppression (methotrexate, mycophenolate) before fibrotic phase — window of opportunity is first 3-5 years. Delayed referral = missed chance for disease modification.

Primary Raynaud's is managed in primary care — benign prognosis, low risk of progression to CTD (<1% over 10 years). Unnecessary referrals burden rheumatology and delay care for high-risk patients. Confident diagnosis and reassurance is therapeutic.

Functional impairment justifies specialist input even in primary Raynaud's — patients unable to work in cold environments, handle frozen food, or perform daily tasks benefit from advanced therapies (PDE5 inhibitors, sympathectomy).

7
Treat

Drug Ladder — Pharmacological management

Start lifestyle measures FIRST. Escalate pharmacotherapy if moderate-severe symptoms or functional impairment.
Mild primary Raynaud's
Lifestyle only First-line
Infrequent attacks, minimal functional impact, no digital damage. Annual review. Offer nifedipine if worsens.
Moderate-severe primary Raynaud's
Nifedipine MR First-line
30 mg OD, increase to 60 mg OD if tolerated and needed. Start low if elderly/frail. Trial 4-6 weeks.
Secondary Raynaud's / digital ulcers
Specialist therapy Refer
Rheumatology will prescribe PDE5 inhibitors, endothelin antagonists, prostacyclin analogues. Not initiated in primary care.
Step 1Nifedipine MR 30 mg OD — Most evidence. Start in October before winter. Warn about ankle swelling (20%), headache (15%), flushing. Check BP at 2 weeks.
Step 2Nifedipine MR 60 mg OD — If partial response. Maximum tolerated dose. Monitor BP, oedema.
Step 3Alternative CCB: Amlodipine 5-10 mg OD (less evidence but better tolerated if nifedipine causes headaches). Diltiazem 60 mg TDS (avoid if cardiac disease).
Step 4Fluoxetine 20 mg OD — Off-label. Some evidence for primary Raynaud's. Consider if comorbid depression/anxiety. Warn serotonin syndrome if other antidepressants.
Step 5Refer rheumatology if refractory to CCB. Specialist options: Sildenafil 25-50 mg TDS, Iloprost IV infusions, Bosentan (digital ulcers in SSc), Botulinum toxin, sympathectomy.
Monitoring
BP at 2 weeks, then 3-monthly. Ask about ankle swelling, headaches. Review symptom diary. Step down dose in spring if symptoms controlled.
Contraindications
Pregnancy (nifedipine relatively safe but use caution), unstable angina, recent MI, severe aortic stenosis, heart failure.
Drug interactions
Nifedipine + alpha-blockers = severe hypotension. Grapefruit juice increases nifedipine levels. CYP3A4 inhibitors (erythromycin, itraconazole) increase levels.

Nifedipine is the only CCB with RCT evidence for Raynaud's. Reduces attack frequency by 30-40% and severity by 30%. NNT = 6 for symptom improvement. Modified-release formulation reduces side effects vs immediate-release.

Lifestyle-first approach respects the benign nature of primary Raynaud's and avoids medicalising a common physiological variant. 60% of patients improve with lifestyle alone. Drugs are reserved for those with functional impairment.

Specialist therapies (sildenafil, iloprost) are not initiated in primary care because: (1) high cost (£200-500/month), (2) require specialist monitoring, (3) used for severe secondary Raynaud's / digital ulcers where stakes are higher. Sildenafil reduces digital ulcer burden by 50% in systemic sclerosis but has no role in uncomplicated primary Raynaud's.

8
Lifestyle

Non-Pharmacological — First-line management for all patients

Lifestyle modification is PRIMARY TREATMENT, not optional add-on. Can reduce attack frequency by 50%.
Keep warm — core temperature Maintain body warmth, not just extremities. Wear layers, thermal base layers, hat (30% body heat lost through head). Pre-warm car, home.
Avoid rapid temperature changes Gradual acclimatisation to cold. Don't plunge hands into hot water during attack (causes painful hyperaemia). Lukewarm rewarming only.
Heated gloves / hand warmers Battery-powered heated gloves (£50-150) effective for outdoor work. Disposable hand warmers in pockets. Electrically heated insoles for feet.
Smoking cessation Nicotine causes vasoconstriction. Smoking doubles attack frequency. Refer stop-smoking service. Vaping also contains nicotine — avoid.
Avoid triggers Identify personal triggers (emotional stress, caffeine, cold drinks, air conditioning). Stress management techniques if stress-triggered. Reduce caffeine if trigger.
Exercise regularly Improves peripheral circulation. 30 minutes moderate exercise 5x/week. Swimming in heated pool ideal (warm + aerobic).
Hand exercises Swing arms in circles, clench/unclench fists to promote blood flow during attack. Avoid immersing in hot water — gradual rewarming only.
Review medications Beta-blockers worsen Raynaud's. Discuss alternatives with GP. OTC decongestants (pseudoephedrine) can trigger attacks — avoid.
Moisturise hands Prevents skin cracking. Use emollient (Diprobase, Epaderm) 3-4x daily. Protects against fissures which can become entry points for infection.
Occupational modification If vibration tools: use anti-vibration gloves, limit exposure duration, take warm-up breaks. Inform employer (HSE duty to reduce vibration exposure).

Core temperature maintenance is more effective than local hand warming alone. Sympathetic vasoconstriction is triggered by core hypothermia, not just local cold. Wearing a hat reduces heat loss and decreases digital vasospasm frequency by 30%.

Smoking cessation is non-negotiable in secondary Raynaud's — nicotine worsens digital ulcers and increases amputation risk 3-fold in systemic sclerosis. Even in primary Raynaud's, smoking doubles attack frequency and severity.

Rapid rewarming harm: Plunging cold hands into hot water causes reactive hyperaemia (painful red phase) and can trigger chilblains. Gradual rewarming with lukewarm water or passive warming is safer and more comfortable.

9
Safety

Follow-Up — Monitoring and safety-netting

Schedule reviews based on severity and risk. Safety-net for complications.
2 weeks
If starting nifedipine: Check BP, ask about side effects (ankle swelling, headache, flushing). Adjust dose if needed. Confirm patient has symptom diary.
6 weeks
Review symptom diary. Assess treatment response (frequency, severity, functional impact). If nifedipine ineffective → increase to 60 mg or consider alternative CCB. If effective → continue, review in 3 months.
3-6 monthly
Primary Raynaud's on treatment: Monitor BP, symptom control, side effects. Consider stepping down dose in warmer months (April-September). Review medication list for culprit drugs.
Annual review
Primary Raynaud's, stable: Check for new systemic symptoms, examine hands for tissue damage, repeat ANA if new features emerge. Reassure if unchanged. Discharge if asymptomatic x2 years and patient confident self-managing.
Safety-net 999
Sudden severe pain, cold pale digit not responding to warming within 30 minutes → Acute arterial occlusion. Black discolouration, tissue breakdown → Critical ischaemia.
Safety-net Same-day
New digital ulcer, non-healing wound. Rapidly worsening attacks (daily, severe pain). New systemic symptoms (fever, weight loss, joint swelling, muscle weakness).
Re-refer if
Primary Raynaud's develops: digital ulcers, asymmetric symptoms, systemic features, positive ANA (if tested), refractory to CCB + lifestyle. Action: Urgent rheumatology referral (may have evolved to secondary).

Evolution to secondary Raynaud's is rare but important to catch. 1-2% of primary Raynaud's patients develop connective tissue disease over 10 years. New digital ulcers, systemic symptoms, or sudden worsening mandates urgent reassessment — do not assume stable primary Raynaud's remains benign.

Seasonal dose adjustment reduces unnecessary drug exposure and side effects. Many patients can stop nifedipine in summer months when attacks are infrequent. Restart in October before winter. This approach improves adherence and reduces ankle oedema burden.

Digital ulcer emergency: Non-healing ulcers in Raynaud's can become superinfected (cellulitis, osteomyelitis) or progress to gangrene requiring amputation. Same-day assessment enables early antibiotics, wound care, and escalation of vasodilator therapy.

Educational use. Pathway based on NICE CKS Raynaud's phenomenon (2023), British Society for Rheumatology guidelines, Cochrane reviews. Always adapt to individual patient context and local guidelines.