Nailfold capillaroscopy in the screening and diagnosis of Raynaud's phenomenon.

Raynaud's phenomenon is in most cases idiopathic, but it may appear as secondary to other diseases. Since clinical evaluation is often inadequate to distinguish between these two forms, simple noninvasive methods are needed for an early diagnosis of the secondary form. The authors used nailfold capillaroscopy to study 58 patients with Raynaud's phenomenon--44 apparently idiopathic and 14 secondary to connective tissue diseases. In all patients affected by secondary Raynaud's phenomenon nailfold capillaroscopy confirmed the presence of an abnormal pattern with typical systemic sclerosis alterations in 5 cases. Twenty-one (48%) of the other 44 patients presented a normal capillaroscopic pattern, 15 (34%) had alterations compatible with long-term idiopathic Raynaud's phenomenon, and 8 (18%) showed abnormal capillaroscopic patterns, 2 of which were identified as the sclerodermic pattern. Nailfold capillaroscopy distinguishes between primary and secondary Raynaud's phenomenon and may be used to identify patients presenting no evidence of underlying disease who could be at risk of developing connective tissue disease.