Most patients presenting with Raynaud's phenomenon have primary Raynaud's phenomenon (PRP) which is common, especially in women. Estimates of prevalence of PRP vary widely: most studies report prevalence to be in the order of 5% in the general population, although some studies have found much higher prevalences. Athough PRP is a “benign” condition in that it does not progress to irreversible tissue damage, it can be associated with significant pain and disability in those severely affected. A key point is that in PRP, abnormalities in the digital vasculature are thought to be purely functional: structural vascular disease (as seen in systemic sclerosis) does not occur. Patients with PRP should have no features of an underlying disease and no abnormalities on examination: they should be antinuclear antibody (ANA) negative, and the full blood count, erythrocyte sedimentation rate (ESR), and nailfold capillaroscopy should all be normal.
Therefore confronted with a patient with Raynaud's phenomenon, the clinician must take a full history and perform a full examination (paying especial attention to the hands and peripheral pulses), looking for any clinical features suggestive of an underlying cause. The basic set of investigations comprises a full blood count, ESR, ANA and nailfold capillaroscopy. Many clinicians would also include a biochemical profile with thyroid function tests and (especially if symptoms are unilateral) a thoracic outlet radiograph to look for a cervical rib. All should be normal in the patient with PRP. Thermography, which measures surface temperature, can help to differentiate primary from secondary Raynaud's phenomenon, but is available only in certain specialist centres.
Most patients with PRP can be reassured and do not require drug treatment: in many patients symptoms improve spontaneously over the years. If drug treatment is required, a calcium channel blocker (sustained release) is generally the first choice, starting at low dosage and gradually increased as tolerated. If the maximum tolerated dose is ineffective, an alternative vasodilator should be tried, although the evidence base for other therapies is very weak.
Disclosure of Interest None declared