Skin Temperature of the Lower Extremities in Patient with leprosy

Recently it has been reported that a patient with leprosy has not only the skid lesion and peripheral neuropathy, but also some involvemeot of peripheral vessels, such as obstruction, stenosis of the small and middle size arteries. These total changes cause a reduced regional blood supply and as a result the skin temperature of the patients extremities become low. In this paper, we studied the skin temperature of 14 patients with lepromatous leprosy using the infrared thermography at rest and after dipping both legs in the water at 15°C. The mean temperature of the legs at rest was significantly lower in these patients than in the controls, and the recovery rate after dipping the cool water was significantly poorer in the patients than in the controls. The difference in the skin temperature at rest between the left and right legs of the patients was significantly larger than that of controls. Colder and warmer portions were observed in the legs of the leprosy patients. The colder portion may be owing to the vascular stenosis and obstruction, while the warmer portion may be caused by the opening of the arterio-venous shunts due to the autonomic nerve disturbance distributed to the vessels. These organic vascular changes could be also responsible for the non-effectiveness of the administration of vasodilators on the skin temperature. Therefore, these results that skin temperature of the leprous patients is not homogemeous. Furthermore these motteld pattern observed in the thermogram indicates the multifocal lesion of the vascular beds. Although in the physical examination the sensory disturbance seems to occur uniformly, the mottled involvement was observed in the thermograms. A measurement of skin temperature by thermography was a more sensitive diagnostic method for the leprous lesion than that of the physical exmination. Thermography seems to be an useful tool for investigating the leprous lesion.