Pathophysiology and classification of the vibration white finger

Skin, arteries and nerves of the upper extremities can be affected by vibra tion exposure. Recent advances in skin and vascular biology as well as new investigative methods, have shown that neurovascular symptoms may be due to different vascular and neurological disorders which should be differentiat ed if proper management is to be evaluated. Three types of vascular disorde r can be observed in the vibration white finger: digital organic microangio pathy, a digital vasospastic phenomenon and arterial thrombosis in the uppe r extremities. An imbalance between endothelin-l and calcitonin-gene-relate d peptide is probably responsible for the vasospastic phenomenon. Moreover, paresthesiae can be due to either a diffuse vibration neuropathy or a carp al tunnel syndrome. A precise diagnosis is then necessary to adapt the trea tment to individual cases. A classification describing the type and severit y of the vascular lesions is presented. Asymptomatic lesions are included f or adequate epidemiological studies and risk assessment of vibrating tools. Monitoring of vibration exposed workers should include not only a question naire about symptoms, but also a clinical evaluation including diagnostic t ests for the screening of early asymptomatic neurovascular injuries.