The abrupt temperature changes in the plantar skin thermogram of the diabetic patient: looking in to prevent the insidious ulcers

Abstract

Background: One of the complications of the diabetes mellitus is the amputation of the lower limbs. This complication may be developed after an insidious ulcer, that may be raised by the peripheral neuropathy or the ischaemic limb, and that the ulcer get infected. That is, to develop an ulcer, in the diabetic patient, three factors should be taken into the account, the autonomic nervous system, the blood supply and the inmune system. Methods: In this work, the thermogram is used to identify regions on the plantar skin with blood supply deficiencies and the behaviour of the thermoregulation process. Within the thermogram of the plantar skin, it can be identify local regions with low and high temperatures that corresponds to ischemic or inflammatory process on that part of the skin. Results: The findings within the 186 thermograms of diabetic patients, obtained from three hospitals and from INAOE facilities, showed, first, the thermograms of the plantar skin of two diabetic patients, acquired in two different times show that the temperature distribution and the average temperatures, vary slightly for a period of weeks. Second, the thermograms of two patients, who both developed insidious ulcers which evolved favourable, demonstrated the importance of the immune system and the drug therapy. These patients are, one who has a Charcot foot, and in the second one, the patient had loss the sensibility of the feet. Finally, the thermograms of two patients, showing abrupt temperature change within small regions in the plantar skin, are discussed. Conclusion: A diabetic patient, with an asymmetric thermogram, as physiological interpretation of the thermoregulation, may indicate a decrease of the blood supply, which may be corroborated by vascular ultrasound. The regions of abrupt temperature change, cold or hot spots, may correspond to ischaemic or inflammatory processes.

Keywords: Abrupt temperature change; insidious ulcers; thermogram; thermoregulation.

Figure 1.

Four thermograms taken in four different dates. At the top of each thermogram is the date of acquisition, and the average temperature is written above each foot. The thermograms numbered 695 and 943 correspond to a female, 59 years old, BMI of 28 kg/m², 14 years with diagnosis of diabetes mellitus. The thermograms numbered 1295 and 1889 are from a male patient, 73 years old, BMI of 23.6 kg/m², 23 years with diagnosis of diabetes mellitus.

Figure 2.

Three thermograms of the plantar skin of a diabetic patient, with the left Charcot foot. The date of the acquisition of the thermogram is at the the top of each thermogram. The average temperatures are written above each foot. This patient is a male, 62 years old, 27 years with diagnosis of diabetes mellitus.

Figure 3.

A thermogram of a diabetic female patient, who has a history of recurrent ulcers on her left foot. The average temperatures are written above each foot. The patient is 62 years old, BMI of 25.4 kg/m², 15 years with diabetes diagnosis.

Figure 4.

(a) Thermogram from a diabetic patient (the average temperatures are written above each foot). The patient is a female, 48 years old, BMI 38.7 kg/m², 12 years with diagnosis of diabetes mellitus. (b) The arrows show the temperatures on the hot spot and some samples of the temperatures surrounding the hot spot.

Figure 5.

The thermogram of the plantar skin of a female, diabetic patient, 60 years old, BMI 24.7 kg/m², 8 years with diagnosis of diabetes mellitus. The average temperatures are written above each foot. The small cold regions on the third toe of the left foot, and on the medial-posterior part of the heel of the right foot, are identified by arrows.