Ultrasonographic and thermographic screening for latent inflammation in diabetic foot callus

Inflammation within the diabetic foot callus may be an earliest, predicting symptom of foot ulcer developing later. The purpose of this study was to identify latent inflammation within the foot callus using thermography and ultrasonography, and to investigate relationship between the inflammatory findings in callus and presence or absence of diabetes.

This was a cross-sectional study of 60 cases with asymptomatic foot callus; the 30 diabetic patients and the 30 non-diabetic matched volunteers. Inflammation was defined using physiological imaging techniques; as skin temperature elevation in thermography and low echoic lesion in ultrasonography.

Sixty-three and ninety-four calli were observed in the diabetic and non-diabetic groups, respectively. The inflammation signs were detected by both of the two techniques in 10% of the calli in the diabetic group. No inflammation was noted in the non-diabetic group (p=0.014).

The inflammation signs presented here were specifically observed in the diabetic group. We consider that the physiological imaging techniques may be valuable screening tools for potential risk of diabetic foot ulcers.