INFRARED THERMOGRAPHY IN THE DIAGNOSIS OF RAYNAUDS-PHENOMENON IN VIBRATION-INDUCED WHITE FINGER

Background: Frequent use of vibrating tools over several years may lea d to a neurovascular disturbance of finger circulation with the develo pment of typical Raynaud's phenomenon, attacks being triggered by vibr ation and/or cold exposure. The condition is recognized as an occupati onal disease and known as vibration-induced white finger (VWF). Aim of the present study was to evaluate the usefulness of infrared thermogr aphy (IRT) with a cold provocation test in the diagnosis of Raynaud's phenomenon in VWF. Patients and methods: 24 patients with the diagnosi s of VWF; previously established by other methods, were compared with 12 marched control subjects. We carried out IRT-measurements simultane ously on both hands before, directly after and 5, 10, 15, 20, and 30 m ins following a 3 min exposure of both hands to a waterbath of 12 degr ees C. The results of temperature measurements of all fingers were ana lyzed and the time to complete rewarming of all fingers was recorded. Results: The basal thermograms did not differ between both groups, whe reas the mean finger temperatures after cold exposure were significant ly lower in VWF-patients compared to controls, with a considerable ind ividual overlap between both groups. Therefore, determination of absol ute finger temperature reveals not to be a useful diagnostic tool in i ndividual cases, but might be helpful for pharmacological studies (gro up-analysis). In contrast to absolute finger temperatures, the paramet er of rewarming time after cold exposure revealed to be diagnostic on an individual basis: a complete rewarming after 15 min indicates a nor mal vascular reactivity and an incomplete rewarming 30 min following t he cold provocation points to an impaired vascular reactivity due to V WF. Conclusions: IRT revealed to be a useful tool in the diagnosis of Raynaud's phenomenon in VWF; and provides a sufficient documentation s uitable for further follow-up examination.