[Capillaroscopy and Raynaud's phenomenon].

Nailfold capillary microscopy is a simple and noninvasive screening test for the etiological diagnosis of Raynaud's phenomenon: --dilating capillary dystrophia, with its large capillary loops (megacapillaries), it is a very specific sign of connective tissue disorders, especially systemic sclerosis; --meshed or branched-tree shaped capillaries are neocapillaries, the meaning of which is very often a dermal vasculitis (S. L. E., rheumatoid arthritis, paraneoplastic Raynaud's phenomenon, or even chilblains); --when numerous abnormal capillary loops and hemorrhages are seen without any special pattern, the diagnosis of idiopathic Raynaud's disease is very unlikely and an extensive biological investigation is needed; --nailfold capillaries look like normal in idiopathic Raynaud's disease and, in this case, only a sharp physical examination and a few biological tests are required. Conjunctival angioscopy is a useful complementary test in some cases when nailfold capillaroscopy is unreliable. Capillary video microscopy is an interesting method for further investigations about the physiopathology of Raynaud's phenomenon.