Reduced epidermal nerve density among hand-transmitted vibration-exposed workers.
OBJECTIVE
The objective of this study was to evaluate ultrastructural changes of epidermal nerve density (END) in workers exposed to hand-transmitted vibration.


METHODS
Ten male subjects with occupational exposure to hand-transmitted tools for 46.9 hours weekly for an average of 6.5 years were included in this study. We performed a skin biopsy from the forearms and compared the END with 10 age- and gender-matched healthy control subjects.


RESULTS
Nine of the 10 subjects had abnormally low END. The END of the exposed workers was significantly lower than the control group (4.1 +/- 2.8 vs 9.0 +/- 4.3 fibers/mm, P = 0.005). The difference remained even after one subject with possible undiagnosed diabetes was not included (4.3 +/- 2.9 vs 9.6 +/- 4.2 fibers/mm, P = 0.005). The reduction of END did not correlate with the abnormality of nerve conduction studies or quantitative sensory testing.


CONCLUSIONS
The reduction of END suggested the involvement of small-diameter nerve fibers among this population, and such a histologic change might either be independent or precede changes of large myelinated nerve fibers.
Liang
Huey-Wen
HW
Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taiwan.
Hsieh
Sung-Tsang
ST
Cheng
Tsuen-Jen
TJ
Du
Chung-Li
CL
Wang
Jung-Der
JD
Chen
Ming-Fong
MF
Su
Ta-Chen
TC
D000328:Adult; D005385:Fingers / Q000294:innervation; D005542:Forearm / Q000294:innervation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D016273:Occupational Exposure; D012867:Skin / Q000294:innervation*; D014732:Vibration / Q000009:adverse effects