Raynaud Phenomenon

Episodic vasospasm of the digital arteries and cutaneous arterioles in response to cold or emotional stress, producing sequential colour change in the fingers or toes. It is classified as primary (idiopathic, no underlying disease) or secondary (associated with an underlying connective tissue disease or other identifiable cause), a distinction with important prognostic and management implications.

Primary Raynaud phenomenon

The commonest form, typically beginning in adolescence or young adulthood, more common in women, symmetrical, without tissue damage, and with a normal nailfold capillaroscopy and negative autoantibody screen.

Secondary Raynaud phenomenon

Associated with systemic sclerosis (in which it is almost universal and often the earliest manifestation, sometimes preceding other disease features by years), mixed connective tissue disease, systemic lupus erythematosus, Sjögren syndrome, and less commonly with occupational vibration exposure, certain drugs (beta blockers, some chemotherapy agents, ergotamines), and thoracic outlet obstruction.

The classical triphasic colour change comprises pallor (vasospasm), cyanosis (deoxygenation of static blood) and rubor (reperfusion hyperaemia), though not all three phases are experienced by every patient.

Episodes are triggered by cold exposure or emotional stress, typically affecting the fingers symmetrically, sometimes the toes, and occasionally the nose, ears or nipples, lasting minutes to a few hours.

Numbness, tingling and pain accompany the colour change, with throbbing discomfort during the reperfusion phase.

Features suggesting secondary disease and warranting further investigation include onset after age forty, asymmetrical or severe episodes, digital ulceration or gangrene, associated symptoms of connective tissue disease (sclerodactyly, telangiectasia, dysphagia, arthralgia, sicca symptoms, photosensitive rash), and an abnormal nailfold capillary pattern.

Digital pitting scars, ulceration and, in advanced secondary disease, critical digital ischaemia with gangrene represent the severe end of the spectrum and are essentially confined to secondary disease, particularly systemic sclerosis.

Diagnosis is clinical, based on the characteristic history of cold or stress induced colour change.

Nailfold capillaroscopy is the key discriminating investigation, showing a normal capillary pattern in primary disease and characteristic abnormalities (capillary dilation, dropout, avascular areas, haemorrhage) in secondary disease associated with systemic sclerosis spectrum conditions, often preceding other clinical or serological evidence of the underlying disease.

Antinuclear antibody testing, with reflex to specific antibodies (anti centromere, anti Scl 70, anti RNP) where positive or where secondary disease is otherwise suspected clinically.

Full blood count, inflammatory markers and creatine kinase if myositis overlap is suspected.

Assessment for thoracic outlet obstruction or vibration exposure where occupational or positional triggers are suggested by history.

Serial follow up is appropriate in patients with features suggesting evolving secondary disease, since a proportion of apparently primary Raynaud phenomenon develops overt connective tissue disease over subsequent years, particularly where capillaroscopy or serology is abnormal at baseline.

Conservative measures form the foundation for all patients: avoidance of cold exposure, layered clothing, hand and foot warmers, smoking cessation (nicotine is a potent vasoconstrictor), avoidance of caffeine and vasoconstrictive drugs where possible, and stress management.

Dihydropyridine calcium channel blockers (nifedipine, amlodipine) are first line pharmacological therapy for patients with frequent or troublesome episodes despite conservative measures, titrated to effect and tolerability, with peripheral oedema and headache as common limiting adverse effects.

Topical nitrates applied to the affected digits are an alternative or adjunct, particularly useful for localised severe episodes.

Phosphodiesterase 5 inhibitors (sildenafil, tadalafil) are used for refractory disease, particularly in secondary Raynaud phenomenon with digital ischaemia, with evidence supporting improved blood flow and ulcer healing.

Intravenous prostacyclin analogues (iloprost) are reserved for severe digital ischaemia, critical vasospasm or non healing digital ulcers, typically administered as inpatient infusions during acute severe episodes.

Endothelin receptor antagonists (bosentan) reduce the development of new digital ulcers in systemic sclerosis associated Raynaud phenomenon, used specifically in that context rather than for primary disease.

Digital ulcer care includes local wound management, infection surveillance and prompt antibiotic treatment where infection develops, with surgical debridement or, rarely, digital sympathectomy for refractory critical ischaemia.

Treatment of the underlying connective tissue disease where secondary Raynaud phenomenon is identified, since disease modifying therapy for the primary condition can improve vascular manifestations.

Reassurance regarding the generally benign course of primary Raynaud phenomenon, with ongoing monitoring for evolution toward secondary disease in those with any atypical features at presentation.