DermatologyTier 1Disease (DEADMAN)

Cutaneous manifestations of systemic diseases - Raynaud phenomenon

Description

Episodic, reversible digital vasospasm on cold or emotional stress
Triphasic colour change - white (ischaemia) -> blue (deoxygenation) -> red (reperfusion hyperaemia)
- All three phases present in only ~1/3 - white alone is enough
Demarcated border is essential - a sharp line between pale and normal skin
- Diffuse mottling/acrocyanosis that does not demarcate is NOT Raynaud
Fingers > toes; also nose, ears, nipples (lactating women)

	Primary	Secondary
Onset	Teens-20s	>=40 yrs
Sex	F>>M (~9:1)	Less skewed
Attacks	Symmetrical, brief (~<15 min), thumb often spared	Asymmetric, severe, prolonged
Tissue injury	None	Ulcers, pits, gangrene
ANA	Negative	Positive
Nailfold capillaries	Normal	Dilated/giant loops, dropout, haemorrhage

Primary: 4-15% of the general population, onset teenage years
F>M; family history in ~1/3
Higher prevalence in cold climates
Raynaud present in 90-99% of systemic sclerosis - usually the first symptom, often by years
Raynaud precedes other CTD features by a median of several years

Imbalance of vasoconstriction and vasodilatation in digital arteries/arterioles + cutaneous AV shunts
- inc alpha-2C adrenoceptor activity (cold-induced translocation to the cell surface)
- inc endothelin-1, dec NO
- Platelet activation, inc thromboxane
Secondary adds fixed structural narrowing (intimal proliferation) to vasospasm
- -> ischaemia at higher ambient temperature, slower recovery, tissue loss

Causes of secondary Raynaud

CTD - systemic sclerosis (commonest), MCTD, SLE, dermatomyositis, Sjögren, RA
Occlusive arterial - atherosclerosis, thromboangiitis obliterans, thoracic outlet, embolism
Occupational - hand-arm vibration syndrome, hypothenar hammer syndrome, vinyl chloride
Drugs - beta blockers, ergotamine, triptans, sympathomimetics, bleomycin, cisplatin, interferon, amphetamines, cocaine
Haematological - cryoglobulinaemia, cold agglutinins, paraproteinaemia, polycythaemia
Other - hypothyroidism, carpal tunnel, POEMS

Clinical diagnosis - photographs on the patient's phone are often the best evidence

The task is to separate primary from secondary

A. History

Age of onset, asymmetry, duration, digital ulcers or pain at rest
Sclerodermatous features: skin tightening, sclerodactyly, dysphagia, reflux, dyspnoea
Drugs, vibrating tools, smoking

B. Examination

C. Nailfold capillaroscopy - the single highest-yield test

Dermatoscope or ophthalmoscope at the cuticle
Giant capillaries, haemorrhages, capillary dropout = scleroderma-pattern -> secondary
Normal pattern + negative ANA = strong negative predictive value for progression to CTD

D. Serology

ANA; if positive -> ENA, anti-centromere, anti-Scl-70, anti-RNA polymerase III
FBE, ESR/CRP, TFT, cryoglobulins, protein electrophoresis where indicated

Predictors of progression to CTD

1. Non-pharmacological - everyone

Whole-body warmth, not just gloves - core temperature drives peripheral vasoconstriction
Stop smoking (absolute in secondary disease)
Avoid vibrating tools, cold immersion, sudden temperature change
Review the drug list - beta blockers, triptans, ergots, stimulants, ADHD medications
Hand warmers, mittens over gloves

2. Vasodilator therapy - escalate by severity

First-line: dihydropyridine CCB - nifedipine (controlled-release)
- Switch to amlodipine if headache/flushing/oedema intolerable
- Start low, titrate; hypotension is the dose-limiting effect
Second-line / add-on
- ARB (losartan), PDE5 inhibitor (sildenafil, tadalafil)
- Topical GTN (to the web space, not the ulcer) or systemic nitrate
- Alpha-blocker (prazosin), SSRI (fluoxetine)
- Antiplatelet + statin where atherosclerotic or in systemic sclerosis
Severe / critical digital ischaemia: IV prostacyclin - iloprost or epoprostenol
- Inpatient infusion over several days

3. Digital ulcer disease (systemic sclerosis)

Bosentan (endothelin receptor antagonist) - prevents NEW digital ulcers, does not heal existing ones
- Hepatotoxic - monthly LFTs; teratogenic
Analgesia, debridement, antibiotics for infection, occasionally digital sympathectomy or botulinum toxin

4. Acute critical digital ischaemia

*Trap: in end-stage scleroderma the digit has lost autoregulation - lowering systemic BP with a CCB can worsen digital perfusion.* Reassess if symptoms worsen on dose escalation

Systemic sclerosis - limited and diffuse
MCTD, SLE, dermatomyositis, Sjögren, RA
Migraine, variant (Prinzmetal) angina, pulmonary hypertension - shared vasospastic tendency
Hand-arm vibration syndrome
Cryoglobulinaemia, cold agglutinin disease, POEMS
Chemotherapy exposure - bleomycin, cisplatin, vinblastine
Hypothyroidism, carpal tunnel syndrome

Primary: benign, stable or improves with age; no tissue loss
- But ~1 in 3 labelled "primary" later prove to have an underlying cause - re-evaluate if the phenotype changes
Secondary: tracks the underlying disease
- Systemic sclerosis -> digital ulcers in ~50%, pitting scars, resorption of tufts, autoamputation
Annual review of a "primary" patient: new ANA, new capillaroscopy abnormality, new sclerodermatous feature
Complications: digital ulceration, infection/osteomyelitis, gangrene, amputation, chronic pain, loss of hand function

6 more sections, plus exam facts

Premium unlocks every note across every specialty, and the full exam fact library behind it.