Thermographic Findings in a Case of Type 2 Diabetes with Foot Ulcer Due to Callus Deterioration

Abstract: A number of studies have reported the usefulness of monitoring skin temperature at local points in reducing the risk of ulceration. Thermography has the advantage of being able to visualize morphological temperature distribution. We reported that inflammation was detected by thermography in 10% of diabetes mellitus (DM) patients with foot calluses, and the area in which increased skin temperature was observed was limited to the callus. However, no reports have described thermographic findings of calluses deteriorating into foot ulcers. We report a case monitoring the skin temperature distribution using thermography, which might be useful for predicting ulceration.

Case: A 53-year-old male patient, diagnosed with type 2 DM, was treated with insulin therapy. The duration of DM was 4 years. He was also diagnosed with dyslipidemia and hypertension. Using thermography, the skin temperature was evaluated in the patient with calluses on the 5th metatarsal heads. Areas of increased skin temperature were observed, involving not only the callused part, but also the plantar arch. We shaved his calluses once a month and explained the importance of his therapeutic shoes to prevent the ulcers. After 43 months, an ulcer developed.

Discussions: Thermographic findings of an extended area of increased skin temperature not limited to the callus may suggest the progression of a callus to ulcer. Expansion of the area of increased skin temperature might show the inflammation or infection extending along the fascia. Based on these findings, thermography could provide a useful assessment of callus in DM patients with a high risk of progression.