A hot spot on the diabetic foot may indicate that an ulcer is about to form. Recent research has focused on foot temperature and inflammation as ways to predict ulcer formation. “Heat is one of the most sensitive things, one of the first things that happens when we begin to have tissue breakdown,” according to Dr. Crystal Holmes, a University of Michigan podiatrist. L Neergaard, Hot Spots Warn of Diabetic Foot Ulcers, Boston Globe, January 15, 2008.
A group at the University of Tokyo recently looked at inflammation under calluses on diabetic and non-diabetic feet. One indication of inflammation was heat. Even though the non-diabetic feet had more calluses, there were no signs of inflammation under the calluses on the non-diabetic feet as determined using physiological imaging techniques. On the other hand, 10% of the calluses in the diabetic group had inflammation. Nishide K, Nagase T, Oba M, Oe M, Ohashi Y, Iizaka S, Nakagami G, Kadowaki T, Sanada H. Ultrasonographic and thermographic screening for latent inflammation in diabetic foot callus, Diabetes Res Clin Pract. 2009 Sep;85(3):304-9. Epub 2009 Jul 7.
In an earlier study Lavery and colleagues studied 173 subjects with a history of diabetic foot ulceration. The study found that patients using an infrared temperature home monitoring device developed fewer ulcers by staying off their feet after detection of high foot temperatures. Lavery LA, Higgins KR, Lanctot DR, Constantinides GP, Zamorano RG, Athanasiou KA, Armstrong DG, Agrawal CM, Preventing diabetic foot ulcer recurrence in high-risk patients: use of temperature monitoring as a self-assessment tool, Diabetes Care. 2007 Jan;30(1):14-20.
These studies support Dr. Holmes point that excessive heat can cause tissue breakdown in diabetic feet. However, the therapies suggested by these studies – staying off your feet – once high foot temperatures are detected are reactive. How can heat build-up on the diabetic foot be prevented?
An interface material such as ShearBan® is specifically designed to prevent friction at targeted locations on the diabetic foot. Friction causes heat. Heat causes skin breakdown. Reducing heat with a low friction material like ShearBan® should prevent skin breakdown. We have case studies and over ten years of clinical experience with ShearBan® that shows this. No, we don’t have a randomized-controlled study . . . yet, but all the evidence going back to Dr. P.F.D. Naylor’s research in the 1950s on friction blisters indicates that a friction management material such as ShearBan® should work to reduce skin trauma on the diabetic foot.