Thermographic analysis and autonomic response in the hands of patients with leprosy

Abstract

BackgroundLow temperatures and slow blood flow may result from peripheral neuropathy caused by leprosy, and the simple detection of cold fingers could already be a preliminary classification for these patients.ObjectiveTo investigate whether infrared thermography would be able to measure this change in temperature in the hands of people with leprosy.MethodThe study assessed 17 leprosy patients who were under treatment at the National Reference Center for Sanitary Dermatology and Leprosy, Uberlândia/MG, and 15 people without leprosy for the control group. The infrared camera FLIR A325 and Therma CAM Researcher Professional 2.9 software were used to measure the temperature. The room was air-conditioned, maintaining the temperature at 25°C; the distance between the camera and the limb was 70 cm. The vasomotor reflex of patients was tested by a cold stress on the palm.ResultsThe study showed a significant interaction between the clinical form of leprosy and temperature, where the control group and the borderline-borderline form revealed a higher initial temperature, while borderline-lepromatous and lepromatous leprosy showed a lower temperature. Regarding vasomotor reflex, lepromatous leprosy patients were unable to recover the initial temperature after cold stress, while those with the borderline-tuberculoid form not only recovered but exceeded the initial temperature.ConclusionThermography proved a potential tool to assist in the early detection of neuropathies, helping in the prevention of major nerve damage and the installation of deformities and disabilities that are characteristic of leprosy.

High resolution ultrasound, nerve conduction study, and other non-invasive investigations in leprosy

“…e temperature is recorded at 0 minutes (initial temperature), 2 minutes and 30 seconds, and 5 minutes (final temperature). [37] e control group and those with lepromatous leprosy showed difference in temperature between the areas supplied by the ulnar and the median nerves, but no difference was noted between the limbs. BL and BB showed a significant difference between the temperatures of the right and left hands, but no difference was noted between the areas supplied by the ulnar and the median nerves.…”

“…In BT, no difference was noted in the mean temperature recorded with respect to the nerve supply or the limb. [37] e temperature difference after the cold stress also differed significantly between the clinical types of leprosy. After the cold stress, BT group could return to and reach a higher than the initial temperature while the lepromatous group was unable to return to the initial temperature in 5 minutes.…”

“…It is a potential tool for early detection of autonomic neuropathy in leprosy, assisting in the prevention of major neural damage, deformities, and disabilities. [37] Temperature changes in patients' hands can be detected by infrared thermography. e patient is made to sit with palms upward in his/her lap.…”

“…Filming of hands is done with the infrared camera for 5 minutes. [37] During filming, after the initial 3 seconds, vasomotor reflex test (autonomic response of the vessel) is performed where a cold stress is delivered on the palms. A cold jet is splashed on the palm to observe the autonomic response of hand's vessels to cold stress (done in both controls and cases).…”

Neurological Complications of Leprosy

“…Patients with lepromatous leprosy were unable to recover initial temperature after cold stress, suggesting that the vasomotor reflex is impaired, while those with the borderline tuberculoid form recovered and actually exceeded the initial temperature. 78 In the United States, there is a persistent concern of underand delayed diagnosis of leprosy. A retrospective study of patients managed at Emory TravelWell center identified 37 patients between 2002 and 2014.…”