Re-evaluation of capillaroscopy of finger nailfold in vibration-exposed workers

Two hundred and ninety-four vibration-exposed workers were examined for vibration disease (VD) for the worker's accident compensation. Most subjects were male. Their ages ranged from 24 to 68 years. Duration of vibration exposure ranged from 3 to 30 years. After acclimatization at 25 degrees C to 27 degrees C for at least an hour, the nailfold capillaries of the ring (or middle) finger were studied with a light microscope. A cold water immersion test (5 degrees C, 10 min) was then performed. The morphological findings of the nailfold capillaries were classified based on the criteria by Fagrell & Lundberg. A hundred and eighty subjects were diagnosed as VD and 75 as non VD, even without taking the capillaroscopic findings into consideration. The classification of the capillarograms retrospectively investigated were as follows, i.e. in 98 VD subjects 40 cases were stage A, 42 stage B, and 16 cases stage C. In 26 nonVD subjects 13 cases were stage A, 10 stage B, and 3 cases stage C, respectively. When the borderline of VD and nonVD existed between stage A and stages B and C, the sensitivity was 59.2%, specificity was 50.0%, and false positive and negative were 50.0% and 40.8%. Relationship between the capillary stage and recovery (%) of the skin temperature during the cold water immersion test was also studied. The recovery in stage C was not always lower than that in stage A. Among them, arteriography was performed in 57 cases. Despite the use of vasodilator, markedly delayed perfusion of the finger tips was observed in 28 cases. Their capillary stages were A in 12 cases, B in 11 and C in 3. The peripheral microcirculatory state in VD should be carefully evaluated in combination with appropriately selected examinations, including finger nailfold capillaroscopy.