by Joseph D. Tabora, M.D.
This article starts below.
Diabetic foot is one of the long-term complications of diabetes mellitus. It is characterized by a non-healing wound on the foot. The wound may become infected, produce a foul-smelling discharge, and may involve the entire foot and spread to the leg. The causes of diabetic foot are diabetic neuropathy and diabetes-induced atherosclerosis.
Diabetic foot & neuropathy
The damage to the nerves brought about by long-standing diabetes alter the mechanics of the foot and the sensation arising from it. The normal arch of the sole of the foot gradually flattens as the neuropathy progresses. This flattening redistributes the pressure points on the sole of the foot. Whereas the heel and the base of the toes are the areas that take the bulk of the pressure when the arch is present, the middle part of the foot gets more pressure as the arch flattens. Since the middle part of the foot is not designed to withstand the constant pressure during standing and walking, this part swells and eventually develops a wound that does not heal.
The development of the non-healing wound is further aggravated by the sensory changes in the foot. While we usually feel pain when we are wounded, and protect the wound by avoiding the use of the injured part of our body, this protective function of pain is lost to the diabetic with neuropathy.
Their sensation of pain is dulled or totally absent. For this reason, they continue to use the injured foot, often unaware that a wound has developed on the sole.
The flattening of the arch of the foot and the loss of the protective pain sensation contribute to the development of diabetic foot.
Diabetic foot & atherosclerosis
The narrowing and hardening of arteries occur faster in the diabetic. This process involves the whole body, including the arteries of the feet. This contributes to the development of diabetic foot by impairing wound healing and by reducing the blood supply to the foot.
For a wound to heal, the components of cellular repair present in the blood must reach the wound. The narrowed blood vessels supplying the wound impair blood flow. The impaired blood flow causes poor wound healing and diminished defense against infection.
Aside from impairing wound healing, the narrowed blood vessels may reduce the oxygen supply to the cells. The blood flow to the toes may be cut off by a sudden clot in the already narrow artery. The clot causes the affected toe to become asphyxiated. When untreated, the toe becomes gangrenous and may be the beginning of an infection that spreads to the legs.
Caring for the feet
Proper care of the feet can reduce the incidence of diabetic foot. Anything that can cause even the slightest scratch to the feet of a diabetic must be avoided, including cuts made when clipping the toenails. The feet must be inspected regularly, as the absence of pain may not alert the patient of a wound. Any wound with redness, discharge and swelling must be properly managed to prevent the spread of infection.