A diabetic foot is a foot that presents with pathology related to diabetes mellitus. These pathologies may include one or more of the following: neuropathy, angiopathy, infection, ulceration and arthropathy.
Diabetic neuropathy is damage to the nerve endings that affected the terminal nerve branched in the feet and hands.
Sensory, motor and autonomic nerves are three different groups of nerves that can be affected.
The sensory nerves are the nerves that enable us to feel pain, temperature and other sensations. The motor nerves are the nerves that control the muscles contractions and enable maintaining strength and tone. The autonomic nerves are the nerves that allow the body to control involuntary functions such as sweating and hydration of the skin.
Diabetic peripheral neuropathy is a slow progressing condition. Some patients have neuropathy long before they are even diagnosed with diabetes. Loss of sensation secondary to nerve damage make a patient vulnerable to foot injuries, developing skin ulcers that can become infected and may not heal. As diabetes also affect the immune response to infection, serious infection may develop and spread from minor injury that may lead to loss of a foot, a leg or even a life.
Causes of Diabetic Foot Conditions
Poorly managed blood sugar in diabetes with excess blood sugar in blood lead to deposition of a sugar metabolites called sorbitol into the nerve cells. These sorbitol drive water into the nerve cells causing them to swell and eventually damage, losing its function. Another theory that explains the neuropathy in diabetes is that neuropathy starting from the constriction of the blood vessels that is caused by diabetes. This leads to decreases circulation reaching to the peripheral nerves that eventually leads to nerve damage.
Damages of various types of nerves can contribute to the development of ulcers. As motor nerves get damaged, the muscle tone changes leading to imbalance across the muscle tendons that eventually progress to deformities in the toes such as hammertoes and bunions. This leads to toes rubbing against the shoe wear that eventually break down the skin creating ulcers. As patient insensate to pain due to numbness of the skin caused by sensory neuropathy this process can continue to occur unnoticed by the patient.
More over, patients with sensory neuropathy are more prone to develop skin blister sense they unable to sensate the pain and temperature difference. Walking barefoot in a warm day might burn the skin and develop blisters. Moreover, walking barefoot carry a high risk of developing skin breaks from stepping on sharp objects.
Diabetic foot symptoms ranges from the neuropathy and angiopathy to the ulcerations and infection complications. Early in diabetic foot, neuropathy manifestation symptoms presents as numbness and tingling in the feet when sensory nerves get involved. In some cases, sensory neuropathy may present with burning pain and discomfort in the feet and legs. As motor nerves get involved in the damaging process, symptoms of muscle weakness, loss of balance and foot deformities with increased pressure in certain weight bearing spots in the foot may present. The autonomic nerves which involuntary regulate the skin hydration and sweet might also get involve in the damage. The later may appear as dry cracked skin that might fissure and create wounds, or might over hydrate the skin leading to skin blister and/or secondary infection with fungus.
History of patient’s symptoms, evaluation of lower extremity circulation and nerves functions are needed to assess the diabetic foot. Your doctor will perform in-office tests on the feet and legs to assess the circulation and assess the nerves reflexes, ability to feel light touch and ability to feel vibration. In few cases, additional nerve testing might be necessary to order to evaluate for any nerve entrapment. More over, your doctor will inspect your feet for any skin changes, ulcers, blisters, infection and evaluate pressure spot that might be at risk of developing calluses or ulcers.
The first line treatment is controlling blood sugar level. Several oral and/or topical medications are available to treat the painful neuropathy symptoms. Surgical nerves releases are considered in cases where anatomical entrapment of the nerves is believed to cause their pain symptoms. Modifying the shoe wear and offloading the pressure spots are commonly used along with different modalities of wound care in order to manage the diabetic wounds.
If you have diabetes, you can prevent the diabetic foot complications by taking simple measures that includes:
Keeping you blood sugar under control.
Proper shoe wear to accommodate the foot deformities and cushioning insoles to protect the skin from ulcerations.
Daily self foot inspection. Notify your doctor for any skin cracks or cuts, swelling, redness, or blisters.
Regularly visit your doctor for examination and to evaluate for any necessary shoe modification or intervention.