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EBMG

Hand-Arm Vibration Syndrome (Vibration-Induced White Fingers)

Paroxysmal whitening of the fingers, triggered by cold, is a typical adverse effect of long-term vibration exposure of the hands.
Vibration may also cause peripheral neuropathy and carpal tunnel syndrome.
The most important condition to be considered in differential diagnostics is primary Raynaud's phenomenon.

Vibration syndrome is caused by working with e.g. a chain saw, rock drill or other hand-held tool driven by motor, electricity or compressed air (e.g. a spanner/wrench, grinder, percussion drill, demolition hammer drill, concrete vibrator).
As chain saws have improved technically, the prevalence and severity of vibration syndrome have decreased among forest workers. Other occupational groups, such as construction and metal workers, foundry fettlers, motor vehicle mechanics, drillers, miners, farmers and gardeners, have become more essential concerning vibration exposure.

Symptoms
- Paroxysmal whitening of the fingers, often in association with cold exposure
- Neurological symptoms such as numbness, tingling, impairment of sensation in and fine motor coordination of fingers, clumsiness and weakened hand force
- Primary Raynaud's phenomenon usually starts before the age of 30 years, whereas acquired hand-arm vibration syndrome has its onset later after a sufficiently long exposure period.
- The development of the vibration syndrome usually requires many years of exposure to hand-arm vibration. Pedestal grinders, however, may get white fingers after exposure for less than one year.
Assessment of exposure
Clinical examination
- Cardiovascular state
- Motor function of the upper extremities
- Neurological examination
Selected tests from the following:
- ESR, basic blood count with platelet count
- antinuclear antibodies, rheumatoid factor
- creatine kinase
- fasting blood glucose
- TSH
- TC2-boundvitamin B₁₂
- gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), carbohydrate-deficient transferrin (CDT)
Differential diagnosis
- Primary Raynaud's phenomenon Raynaud's Phenomenon (RP) or White Finger Disease
- Connective tissue diseases
- Causes of neuropathy: diabetes, alcohol, hypothyroidism, vitamin B₁₂ deficiency
- Smoking
- Traumas
- Stenoses in proximal vessels (thoracic outlet syndrome, TOS Thoracic Outlet Syndrome)
- Obstructive angiopathy
- Cryoglobulinaemia
- Drugs (ergot alkaloids, beta-blockers)

A patient who has typical symptoms that are associated with vibration and not explained by other diseases is referred to the occupational health service.
- Interventions at the workplace
- If required, the patient is referred to an occupational medicine specialist unit for further investigations.
Detection of Raynaud's phenomenon with finger plethysmography (special equipment)
ENMG, measurement of thermal and vibration sensation thresholds

Reducing the exposure to vibration is most important.
If vibration acceleration (describing the intensity of vibration) exceeds the action limit of 2.5 m/s² for hand vibration, the manufacturer, importer or vendor of the machinery has to provide information on vibration. The employer has to be aware of the tools, machines, devices or areas where the daily average of vibration exposure exceeds the aforementioned action limit. If the action limit is exceeded, the employer must draw up a vibration prevention programme for limitation of exposure and arrange health inspections for workers exposed to vibration.
If vibration acceleration exceeds 5.0 m/s² which is the limit for hand vibration, immediate actions are required in order to reduce vibration exposure.
Other working conditions (coldness, noise) should be improved.
Alternative working methods, less vibrating tools, checking of the adjustments of the machinery, vibration dampening
The duration of exposure is limited by e.g. work rotation or arrangement of pauses.
Warm gloves
Smoking cessation
Consider changing of medication that provokes vasoconstriction (e.g. beta blockers).
Pharmacological treatment
- See article Raynaud's phenomenon (RP) or white finger disease Raynaud's Phenomenon (RP) or White Finger Disease

Diminishing exposure to vibration usually leads to reduction or disappearance of symptoms.
Whitening of the fingers may disappear after the exposure is stopped, but numbness may even increase.
If the symptoms have lasted for a long time, they often may not improve after the exposure ends. Tendency to white fingers and/or sensory disturbances, clumsiness and tendency to pain may remain as persistent symptoms that cause impairment.
Change of occupation should be considered if hand-arm vibration syndrome has been diagnosed and exposure cannot be significantly reduced, especially if the work tasks require deft fingers or working in cold and symptoms in the upper extremity are extensive.