Monitoring neuropathic ulcer healing with infrared dermal thermometry

The purpose of this study is to prospectively evaluate skin temperatures at the site of neuropathic ulceration before, during, and after wound healing using the contralateral extremity as a physiologic control and to evaluate variables that may influence skin temperature gradients. We studied 17 male and 8 female diabetics with mean age and duration of diabetes of 52.4 ± 11.6 years and 13.8 ± 7.8 years with grade I (Meggitt-Wagner) plantar ulcers. All patients received weekly cast changes with wound and skin temperature assessments. After healing, all patients were fitted with prescription shoe gear. Temperatures on the ulcerated foot were higher than those on the contralateral foot on initial presentation (91.1 vs. 84.2°F, t = 8.9, p < 0.0001, 95% CI 5.3 to 8.5), but the same following healing. Patients with vibration perception thresholds greater than 45 V had wider skin temperature gradients than those with lesser degrees of sensory neuropathy (8.8 ± 4.1 vs. 4.9 ± 2.5°F, p = 0.007). Additionally, subjects with toe brachial indices below 0.60 had greater skin temperature gradients at the site of ulceration than those with higher indices (9.4 ± 4.0 vs. 5.8 ± 3.4°F, p = 0.01). There was not a significant difference in initial skin temperature gradients by duration of wound prior to treatment, duration of wound healing, sex, maximum plantar pressure, or hemoglobin A1C level.