Raynaud’s phenomenon, digital ulcers and nailfold capillaroscopy

Raynaud’s phenomenon (RP) is the clinical manifestation of defect of the thermoregulatory vessels in the skin and of medium and small vessels in the peripheral arterial system. Triphasic colour changes (pallor, cyanosis and hyperaemia) occur as an exaggeration or perturbation of normal responses to cold ambient temperature or emotional stress. RP occurs primarily in the fingers with relative sparing of the thumbs. It can also occur in the toes, tongue, ears and nose. In patients with SSc, RP can progress to digital ulcerations and (less frequently) to critical ischaemia and is then associated with significant pain and disability, including work disability. This chapter reviews the pathogenesis of RP (including the normal physiology of the thermoregulatory vessels), imaging techniques (with a focus on nailfold capillaroscopy) and approaches to treatment, including in the patient with digital ulcers or critical ischaemia. New approaches to treatment are discussed.