[Raynaud's syndrome in lumberjacks using chain saws. Epidemiology, clinical and capillaroscopic findings].

The overall incidence of Raynaud's syndrome in lumberjacks using a mechanic chain saw in France is at least 45%; workers exposed to the risk for more than 3 years have an incidence of about 60%. Vibrations are probably directly responsible for the disease, while among the other favorizing factors the different winter climatic conditions do not appear to be relevant, and this is the case with conventional vascular risk factors, apart perhaps for hypertension. A history of injury to hands is significantly more frequent in affected subjects possibly related to a relative digital cutaneous hypo-esthesia. Capillaroscopy shows organic microangiopathies with reduction in number of nail-bed capillaries and functional angiopathies of arteries of hand in the form of abnormal spasm induced by cold. Technical progress by the use of chain saws has markedly reduced incidence of this occupational disease, but in France it would appear that only modifications in working conditions of lumberjacks could reduce the incidence of the disease.