Vibration damage to the hand: clinical presentation, prognosis and length and severity of vibration required.

Exposure to vibrating hand-held tools can cause a variety of vascular and neuromuscular symptoms collectively named Hand-Arm Vibration Syndrome (HAVS). The clinical presentation of this syndrome includes paraesthesiae or tingling in digits, pain or tenderness in the wrist and hand, digital blanching, cold intolerance, weakness of the finger flexors or intrinsic muscles and discolouration and trophic skin lesions of the fingers. HAVS can be reversible, at least in the earlier stages, but resolution of symptoms is unusual in more severe cases, and continued use of vibrating tools in such cases is unwise. The duration of exposure needed to produce HAVS cannot be readily defined. This is due not only to different individual susceptibilities to vibration, but also to the different physical characteristics of the vibration exposure. There is a cumulative effect of vibration on both the vascular and sensorineural components of HAVS and these components appear to occur and progress independently of each other.