Pathophysiology of white fingers in workers using hand-held vibrating tools

Area of Science:

• Occupational Health
• Vascular Physiology
• Neurology

Background:

• The pathogenesis of white fingers (VWF) in users of hand-held vibrating tools is not fully understood.
• Current theories involve autonomic dysfunction, possibly due to limbic system damage, and chronic exposure to environmental stressors.
• Observed chronic autonomic disturbances include cardiac changes, hearing loss, and reduced toe skin temperature.

Purpose of the Study:

• To clarify the pathogenic events and primary lesion localization in vibration-induced white fingers.
• To investigate the multifactorial etiology of Raynaud's phenomenon in the context of vibrating tool use.
• To propose a model for the manifestation of vasoconstriction and white fingers.

Main Methods:

• Review of existing literature on vibration disease and white fingers.
• Analysis of observations related to chronic autonomic disturbances.
• Consideration of proposed pathogenetic mechanisms including sympathetic hyperactivity, alpha-adrenergic receptor changes, and endothelial dysfunction.

Main Results:

• While sympathetic hyperactivity is implicated, damage to finger skin vaso-regulatory structures is also involved.
• Pathogenesis likely includes altered alpha-adrenergic mechanisms and endothelial dysfunction with impaired endothelial-derived relaxing factor.
• The roles of vessel lumen reduction, blood viscosity, and confounders like cold, smoking, and susceptibility are unclarified.

Conclusions:

• A multifactorial etiology is likely for Raynaud's phenomenon in vibrating tool users due to physiological complexity.
• An abnormal sympathetic efferent level is important for VWF symptom production.
• A model is suggested where vasoconstriction results from a narrowed gap between symptom threshold and sympathetic activity levels.