Care of the Diabetic Foot

By Rodney Snow, MD

Diabetes is a major problem that we deal with in the United States and Alabama is certainly one of the states near the top of the list with a large percent of the adult population that are diabetics. In the U.S. it is estimated that up to 17% or more of the adults are diabetics. Close to 14% of all US health care expenditures are related to diabetes and its complications with about half of the cost related to complications such as heart attacks, strokes, kidney failure including dialysis, degrees of blindness (diabetic retinopathy) and diabetic foot ulcers (DFU) with various levels of amputation.

Human nature is such that most do not even think about their feet unless an issue developed that causes pain or some other issue that gets our attention. We just take our feet for granted and move along. Any diabetic that develops a foot ulcer (DFU), no matter how small or simple can result in that person losing their leg. It is estimated that the lifetime risk of the diabetic getting diabetic foot ulcers or other foot complication is up to 25%; therefore 25 out of 100 diabetics are going to get a foot ulcer that can lead to loss of their limb.

Diabetic peripheral neuropathy is the main factor that leads to diabetic foot issues with risk of ulceration and then possible limb loss along with peripheral arterial disease. To prevent peripheral neuropathy controlling of one’s blood sugar is vital. Elevated blood sugar leads to the development of neuropathy in various ways, which causes damage to the nerves. It usually develops first in the feet, distally in the toes progressing up into the legs and later into the hands. However, all nerves in the body can and will be damaged over time. The neuropathy leads to damage of the sensory nerve function so there is gradual loss of sensation or feeling in the foot that’s why it’s is so important in protecting the foot from injury. We all learn to not do something when it causes us pain, such as touching a hot stove in which we learn not to repeat that behavior. The loss of protective sensation in the foot from the diabetic neuropathy allows trauma and injury to occur. In addition, the motor nerve function is also damaged so there is weakness in the muscles and the muscles get smaller especially in the foot. This allows deformities in the foot such as hammer toes or claw toe deformity to have more pressure in one location over another on the bottom of the foot allowing callus formation. In addition, neuropathy affects the nerves that regulate the sweat glands and regulates the micro blood flow in the skin. The diabetic foot becomes dry leading to cracks and scaling of the outer layer of skin. With the deformities, shoes will not fit properly leading to areas of pressure and or friction that leads to blisters and calluses. The blister can open, getting infection and or causing an ulcer to develop.  A crack can occur in the callus which can get infected leading to an ulcer. Without protective sensation, even minor trauma can lead to issues because with no pain the trauma is overlooked until it is noticed from bleeding or infection.

When the diabetic patient sees his primary care provider he should go ahead and take his shoes and socks off at each visit for foot inspection.  At least once each year a complete examination of the feet should be done. The diabetic patient should ask for the foot exam each year. In addition, blood flow to both feet should be assessed. When sensory function is altered, different foot ware should be considered.  Shoes should be wide and deep enough to allow for custom inserts, to distribute the pressure on the bottom of the foot more evenly. With the mechanical wear and continuous changes that occur in the foot, shoes and inserts need reevaluation at least every six months.

The diabetic patient should be educated and understand their responsibility to check their feet daily and take proper care of them, if the individual wishes to keep them over time, along with blood sugar control, diet, and not smoking, which accelerates artery damage. One should avoid activities that can injure the feet such as walking barefoot or even in sock feet, using a heating pad, hot water bottle, or putting ones feet on a furnace vent or near a space heater. Do not step into a bathtub or soak ones feet without testing the water temperature. Do not spend extra time on ones feet looking for other ways to ambulate or exercise. Trimming nails and other bathroom surgery that leads to breaks in the skin on the feet should be avoided, allowing Podiatry or other healthcare providers to do even the minor procedure. Feet need to be washed daily in lukewarm water with a mild soap (such a Dove®) and apply generously moisturizing lotion or cream. Because of the dryness it will require application of the lotion or cream more than once daily. The diabetic must check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage may be hidden. Use a mirror, if it is difficult to see all parts of the feet or ask a family member or caregiver to help. Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break all new shoes in slowly to prevent any blisters. When blisters develop, do not open them and get pressure off that area to allow the blister to heal.  The top layer of skin comes off on its own. Keeping calluses soft as possible and filed down, prevents the build of additional callus and development of a blister underneath or cracking. Most diabetic foot ulcers develop from blister or calluses.

If an ulcer develops, the time to get it healed is when it is first noticed. Seek medical attention and keep in mind antibiotics alone will not heal the ulcer. Remember that one should not be able to walk without pain with an ulcer on their foot. This is the problem, the lack of the pain from the neuropathy. For the ulcer to heal, the pressure must be taken off of the ulcer so the patient must not walk on the ulcer or some method must be provided to relieve that pressure.  If not, the ulcer will not heal and will get larger and deeper, with infection developing at some point. The price for healing must be paid and with the lack of pain, our mind must guide us to accomplish the appropriate things needed for healing, to prevent a greater price that could be prevented.