Nailfold capillary microscopy for evaluating hand-arm vibration syndrome

ABSTRACT

OBJECTIVES: We evaluated nailfold capillary abnormalities in patients with hand-arm vibration syndrome using nailfold capillary microscopy. METHODS: Fifty workers who underwent a special health examination because of exposure to hand-arm vibration at Ulsan University Hospital in 2012 (exposed group) and a control group of 50 white-collar employees were evaluated through a questionnaire survey regarding their present tasks, types of tools used, vibration exposure duration, use of protective wear, and medical history. Then, an occupational physician performed a physical examination for any hand deformities, skin problems, or motor and sensory dysfunctions of the upper extremities. The nailfold capillary morphologies (tortuous, crossing, bushy, meandering, branching, hemorrhage, avascular area, enlarged, and giant), capillary dimensions (afferent, top, venous, total width, and length), and specific counts (crossing and branching) on both fourth fingers were determined by a rheumatologist. Thereafter, the exposed subjects were assessed according to the Stockholm workshop classification scale. In total, 8 and 6 subjects in the exposed and control groups, respectively, were excluded from the study because of poor capillary microscopic image quality. In addition, 24 subjects in the exposed group with Stockholm vascular stage 0 were excluded. Finally, capillary morphology, dimensions, and specific counting were compared between the exposed (n = 18) and control groups (n = 44). RESULTS: The exposed group had significantly greater crossing capillaries and abnormal capillary numbers that included crossing capillaries (crossing, branching, bushy, and meandering) but smaller branching and abnormal capillary numbers that excluded crossing capillaries (branching, bushy, and meandering) than the control group did. No significant difference in capillary dimensions was observed between the two groups. Despite the adjustment for age, smoking status, and underlying diseases, the statistical significance was unchanged. In the specific counting of the type of capillaries, the exposed group had a significantly higher total crossing count but fewer total branching count than the control group did. However, no statistical significance resulted after adjustment for age, smoking status, and underlying diseases. CONCLUSIONS: In this study, the exposed group had significantly more crossing capillaries and a higher crossing count than the control group did.