A patient is having their foot bandaged as suffering with diabetic septic foot. Unregulated hyperglycaemia (high blood glucose levels) leads to non-enzymic glycation of proteins in the walls of the blood vessels. This compromises the basement membrane of the smaller arterioles and capillaries, enabling the movement of proteins across it. As a result, the colloid pressure of the tissues in the periphery is increased and interstitial fluid accumulates. Peripheral neuropathy frequently occurs due to the reduced oxygen delivery to the nerves as a consequence of damaged capillaries. This loss of sensation results in an increase in accumulated foot trauma from abnormal weight-bearing, leading to the development of callouses; and later ulcers. Diabetics are already more susceptible to bacterial infections as high blood glucose inhibits some components of the immune system. Coupled with a loss of the epidermis and glucose-rich interstitial fluid, the diabetic foot provides the perfect medium for bacterial growth.
