Using Noncontact Infrared Thermography for Long-term Monitoring of Foot Temperatures in a Patient with Diabetes Mellitus.

Foot complications in persons with diabetes mellitus (DM) are associated with substantial costs and loss of quality of life. Increasing evidence suggests changes in skin temperature, measured using an infrared thermographic system (IRT), may be a predictor of foot ulcer development in patients with DM. The purpose of this case study is to describe the long-term IRT findings and overall clinical outcomes of a patient with DM and peripheral vascular disease. Foot temperature measurements using IRT were obtained slightly more than 1 year before and immediately following endovascular treatment of a 76-year-old man, a nonsmoker with type 2 DM, hypertension, and ischemic heart disease with cardiac arrhythmia. Although he was otherwise asymptomatic, the infrared measurement showed an average temperature difference of 2.3˚ C between the left and right foot until he developed a small, trauma-induced wound on the left foot, at which time left foot temperature increased. He was diagnosed with rectosigmoid adenocarcinoma, underwent surgery and chemotherapy, and subsequently was evaluated for peripheral vascular disease. Before undergoing peripheral angiography and percutaneous transluminal angioplasty, IRT evaluation showed a hot spot on the left heel. Immediately following endovascular treatment, the mean temperature difference between the right and left foot was low (0.2˚ C), but a Stage I pressure ulcer was visible on the left heel. Skin breakdown in that area was observed 2 months later, and the wound continued to increase in size and depth. The patient died shortly thereafter due to complications of cancer. In this case study, a series of infrared images of foot skin temperatures appeared to show a relationship with blood circulation and wound/ulcer development and presentation. IRT has the ability to instantaneously measure the absolute temperature of the skin surface over a large area without direct skin contact. However, the devices are very sensitive and prospective clinical studies to determine the validity, reliability, sensitivity, and specificity of these measurements for routine use in patients who are at risk for vascular disease and/or foot ulcers are needed.