Reduced epidermal nerve density among hand-transmitted vibration-exposed workers

Abstract

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. Copyright © 2006 by American College of Occupational and Environmental Medicine.