Longitudinal study on factors related to the course of vibration-induced white finger.

Follow-up surveys were conducted in 1982 and 1988 to investigate factors affecting the course of vibration-induced white finger (VWF). Subjects were 353 patients, aged 40 to 70 at the start of the 1982 survey, who were receiving treatment for hand-arm vibration syndrome. Between 1982 and 1988, the attacks of VWF decreased, while numbness and pain in the hand changed slightly. Finger skin temperature showed a tendency to increase, but recovery time in nail compression tests was unchanged. Vibration perception threshold and grasping power tended to become worse. Of the 177 patients with VWF in 1982, 55 (31%) had no VWF in 1988. The improvement in VWF depended on its severity assessed by the frequency of attacks, the extent of the affected finger phalanges and the Stockholm vascular (V) stage at the start of the 1982 survey. The improvement was observed in 46% of the 1V (mild) stage cases, against only 17% of the 3V (severe) stage cases. Patients in the 2V (moderate) and 3V stages had lower finger skin temperature than those without VWF (the 0V stage). Patients with milder VWF seemed more likely to improve. Continued use of vibratory tools was found to be an unfavourable factor for improvement of VWF. Age, smoking and drinking habits, and medical complications showed no significant effects on the course of VWF.