[Definition and epidemiology of vascular acrosyndromes].

Vascular acrosyndromes group several disorders around Raynaud's phenomenon, characterized by a distal involvement and a vasomotor pathogenesis. Their exact mechanisms remain unknown, but epidemiological data favour disturbances of thermoregulation: cold climate, outdoor occupation and low body mass index are significant risk factors for most of them. Acrosyndromes with vasoconstriction are highly prevalent in France: 10 to 15% for Raynaud's phenomenon and acrocyanosis; 2 to 6% for chilblains. Acrosyndromes with vasodilatation (acrocholose, erythermalgia) are much rare. There is no link between Raynaud's phenomenon and tobacco use, alcohol consumption, oestrogen treatment, carpal tunnel syndrome or thoracic outlet syndrome. By contrast, the role of connective tissue diseases and occupational disorders (vibration exposure and hand-hammer syndrome) are established.