Vibration-induced white finger syndrome and carpal tunnel syndrome among Finnish metal workers.
OBJECTIVE
Officially 10-26 cases of vibration-induced white fingers (VWF) have been reported annually in Finland. It has been suggested that the numbers are underestimated. The purpose of the present study was to estimate the cumulative exposure to hand-arm vibration (HAV) and the prevalence of clinically diagnosed cases of VWF and carpal tunnel syndrome (CTS) in a population of Finnish metal workers and to determine the symptoms and clinical tests that would best predict the diagnosis.


METHODS
A questionnaire on vibration exposure at the workplace and symptoms of the upper extremities was sent to a sample (n = 530) of members of the local Metalworkers Union. Those who reported finger blanching, numbness or tingling of the fingers or symptoms of CTS were invited to take part in clinical examinations. Their cumulative lifelong exposure to HAV was evaluated. Those whose symptoms referred to VWF or CTS were given a cold provocation test with the measurement of finger systolic blood pressure and electroneuromyography of the upper arms.


RESULTS
Altogether 285 metal workers (54%) responded to the questionnaire, and 24 new cases of VWF (8.4%) and 12 cases of CTS (4.2%) were diagnosed. In the group of VWF patients, seven workers had both VWF and CTS. All of the workers diagnosed as having VWF also had numbness or tingling in their fingers. Consequently, questions concerning numbness and tingling, a two-point discrimination test, Phalen's test, and Tinell's test had a high predicting value for VWF. The exposure time of the VWF cases did not differ significantly from that of the study group as whole, but the cumulative exposure index was significantly higher.


CONCLUSIONS
The results suggest that VWF is underdiagnosed in Finland. In screening for the health effects of HAV, sensorineural symptoms of hands should be carefully inquired about and examined in patients complaining of white fingers. More education on the recognition and evaluation of HAV exposure and its health effects is needed.
Sauni
Riitta
R
Finnish Institute of Occupational Health, Tampere, Finland. riitta.sauni@ttl.fi
Pääkkönen
Rauno
R
Virtema
Pauliina
P
Jäntti
Ville
V
Kähönen
Mika
M
Toppila
Esko
E
Pyykkö
Ilmari
I
Uitti
Jukka
J
D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D004576:Electromyography; D005260:Female; D005387:Finland / Q000453:epidemiology; D053421:Hand-Arm Vibration Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects; D015995:Prevalence; D011795:Surveys and Questionnaires; D014732:Vibration / Q000009:adverse effects
Occup Med (Lond). 2007 Jan;57(1):25-9
16928782
Int Arch Occup Environ Health. 2006 Sep;79(8):665-71
16523316
Occup Med (Lond). 2003 Aug;53(5):331-6
12890833
Ind Health. 2005 Jul;43(3):527-34
16100929
Int Arch Occup Environ Health. 2005 Jun;78(5):363-8
15883818
Ind Health. 2005 Jul;43(3):542-7
16100931
Occup Med (Lond). 2003 Aug;53(5):337-41
12890834
Occup Med (Lond). 2007 Jan;57(1):57-66
17082517
Am Ind Hyg Assoc J. 1990 Apr;51(4):179-84
2327329
Int Arch Occup Environ Health. 1998 Nov;71(8):509-19
9860158
Scand J Rehabil Med. 1990;22(3):127-34
2244189
Disabil Rehabil. 2005 Nov 30;27(22):1373-80
16372432
Occup Med (Lond). 2005 Mar;55(2):139-41
15757991
Int Arch Occup Environ Health. 2002 Jan;75(1-2):6-13
11898878
Arch Phys Med Rehabil. 1985 Feb;66(2):69-74
3970660
Occup Environ Med. 2000 Apr;57(4):218-28
10810107
Br J Ind Med. 1992 Jan;49(1):53-62
1733457
Appl Occup Environ Hyg. 2000 Mar;15(3):291-302
10701292
J Appl Physiol Respir Environ Exerc Physiol. 1977 Nov;43(5):907-10
591484
Scand J Work Environ Health. 1998 Apr;24(2):138-44
9630062
Work Environ Health. 1974;11(2):118-31
4456890
Int Arch Occup Environ Health. 1980;46(3):251-66
7450890
Scand J Work Environ Health. 1987 Aug;13(4):275-8
3433028
Arch Neurol. 1994 Apr;51(4):416-20
8155019
Int Arch Occup Environ Health. 2002 Jan;75(1-2):37-42
11898875
J Hand Surg Br. 2005 May;30(2):199-203
15757775
Scand J Work Environ Health. 1986 Oct;12(5):439-47
3538376