The utility of skin surface temperature measurement in the prediction of diabetic foot ulceration.

Aim: Temperature is a marker of inflammation. Research has shown that by measuring skin surface temperature in those with a history of diabetic foot ulceration (DFU), tissue damage can be identified early and reduce rates of subsequent DFU. This study considered whether measuring skin surface temperature using infra-red thermometry can identify early tissue damage and inform clinical practice in a general population with Diabetes Mellitus (DM).

Method: The data presented was taken from a prospective observational study of risk factors in patients with Diabetes. As part of this study, temperature measurements using the Flir E6 Infra-red camera were taken from 216 individuals attending outpatient diabetes clinics in a large urban teaching hospital in Ireland as part of a comprehensive diabetic foot assessment. Measurements were taken at foot sites associated with increased risk at baseline received repeat temperature measurement on 2 subsequent occasions in the following week. Any ulceration was subsequently recorded.

Results: Discussion: Of the 216 participants, 4 % (n = 9) developed visual ulceration within 7 days. All of these had been identified at high risk at baseline assessment and had a history of foot disease. A temperature differential of ≥2.2 °C between sites of interest was recorded. Temperature ranges varied from 29.1 °C to 37.6 °C. High temperature was considered if over 35 °C. Of those who developed a diabetic foot ulceration within the 7 day follow up period, 78 % (n = 7) had a high temperature. The remaining 22 % (n = 2) who developed ulceration had a temperature reading in the normal range.

Conclusion: Elevated skin surface temperature was seen prior to the development of DFU in all cases in this study. Initial analysis suggests that neither the 35 °C threshold nor a 2.2 °C temperature difference is indicative of inevitable tissue damage in this population due to the high number of false positives seen.