Explain diabetic foot clearly once and for all

| What is diabetic foot?

Diabetic foot refers to lower limb infection, ulceration and/or deep tissue damage caused by neuropathy and varying degrees of vascular disease in diabetic patients.

| What are the clinical manifestations of diabetic foot?

1. Manifestations of neuropathy:

The skin of the affected limb is dry without sweat, and there is tingling, burning pain, numbness, decreased or absent sensation in the extremities, which becomes like a stocking, and there is a feeling of stepping on cotton wool when walking.

2. Manifestations of vascular disease:

Intermittent claudication, resting pain, pale, thin, dry skin, no sweating or decreased skin temperature, even hair loss, thickening of toenails, disappearance of posterior tibial artery and dorsalis pedis artery pulse.

| What are the complications of diabetic foot?

1. Ulcers

Diabetic foot ulcers are the most common complication of diabetes. The incidence of diabetic foot ulcers in diabetic patients is 15%. The most common causes of ulcers are: neuropathy, deformity, corpus callosum, increased plantar peak pressure, peripheral vascular disease, penetrating injuries and shoe-related. A history of previous ulcers is the main risk factor for new ulcers or amputations.

2. Charcot arthropathy

Charcot neuroarthropathy is a noninfectious disease that causes progressive destruction of bones and joints due to peripheral neuropathy.

The main problem of the Charcot joint of the foot is a series of lesions caused by the wear of the shoes and the protruding bone spurs of the foot when walking with weight. This situation often leads to repeated ulcers in the high-load-bearing areas. Once the ulcer occurs, external bacteria will further cause subcutaneous or deep infection of the foot through the ulcer channel, and may eventually lead to amputation.

3. Infection

Autonomic dysfunction leads to skin and soft tissue destruction, causing invasion of exogenous bacteria. Changes in chemical tropism lead to inefficient leukocyte response. In addition, hyperglycemia, decreased oxygen partial pressure, and malnutrition can jointly cause tissue edema, acid accumulation, hyperosmosis, and inefficient anaerobic metabolism. Such an environment is suitable for bacterial growth and hinders the function of leukocytes. In addition, vascular disease can limit the transport of antibiotics, further reducing the efficiency of bacterial clearance, leading to local soft tissue infection and even the formation of osteomyelitis.

4. Toe deformity

Motor neuropathy manifests as loss of intrinsic muscle function and contractility of the foot, leading to claw toe deformity, which can also cause plantar ulcers.

| Why do ulcers occur?

Autonomic neuropathy can lead to abnormal perspiration function of the feet, and cause the skin of the feet to become hard, dry and severely keratinized, which increases the fragility of the skin, reduces its elasticity, and is prone to cracking. Thickening of the skin leads to cracking, especially in the thicker part of the corpus callosum on the sole of the foot. Cracks are a route for the spread of bacteria, leading to infection. Autonomic neuropathy can also lead to impaired skin temperature regulation. The skin is slow to respond to high temperatures, which can lead to skin damage and infection.

What are the tests for diabetic foot?

1. Neurological examination:

1) 10g nylon thread inspection method

2) Quantitative sensory testing (QST):

3) Pathological reflexes:

4) Vibration sense:

This test is a semi-quantitative test of deep tissue sensation. Before the test, the handle of a vibrating tuning fork is first placed on the patient's mastoid process to allow the patient to feel the vibration of the tuning fork, and then placed on the bony protrusions of both feet for comparative examination (the medial side of the first metatarsophalangeal joint, the medial and lateral malleolus).

5) Nerve Conduction Velocity (NCV):

It is generally believed that patients with two or more slowed NCVs combined with other symptoms, signs and auxiliary examinations may be suspected of having diabetic peripheral neuropathy (DPN).

2. Vascular disease examination:

1) Skin temperature examination: Infrared skin temperature examination is a simple and practical method to evaluate local blood supply. It is best to use temperature difference to judge limb blood supply.

2) Ankle-brachial index (ABI): It reflects the blood circulation status of the limbs. The normal value is 0.9-1.3, 0.71-0.89 is mild ischemia, 0.5-0.7 is moderate ischemia, and <0.5 is severe ischemia. Patients with severe ischemia are prone to lower limb (toe) gangrene.

3) Toe-brachial index (TBI)

4) Transcutaneous oxygen partial pressure (TCPO2): In normal people, TcPO2 on the dorsum of the foot is >40mmHg; if it is <30mmHg, it indicates insufficient peripheral blood supply, the foot is prone to ulcers, or existing ulcers are difficult to heal; if TcPO2: <20mmHg, there is almost no possibility of healing of foot ulcers.

5) Color Doppler ultrasound of lower limb blood vessels: Vascular color Doppler examination is non-invasive and simple. It can understand the status of arteriosclerotic plaques and whether there is arterial stenosis or occlusion. It is suitable for large-scale screening of vascular diseases.

6) Lower limb artery angiography: can show whether the blood vessels are narrowed or blocked

How to care for patients with diabetic foot

1. Check your feet

Check your feet every day. If you don't have good vision or flexibility to check every part of your foot, use a mirror or have a friend or family member check for you. Check each foot thoroughly for cracks, blisters, bruises, red spots, cuts, and ulcers. Make sure the skin between your toes isn't excessively moist.

2. Wash your feet

Wash your feet daily with warm water and mild soap.

As long as you don't have neuropathy in your arms or hands, always use those areas to test the water temperature, otherwise have someone else test it for you. Remember that even if your feet are burned, you may not feel it. Dry between your toes carefully and gently, without rubbing the spots. Do not soak your feet.

3. Be careful of burns

If your feet are cold at night, wear socks to bed. Do not use heating pads, hot water bottles or other heat sources to warm your feet. Irreversible damage can occur in a short time. Do not walk on hot surfaces without shoes, as this can damage your skin.

4. Skin care

To keep your skin moisturized after bathing, apply a thin layer of lubricant or cream, such as petroleum jelly or a specialized diabetic moisturizer. Do not use creams, lotions, or ointments between your toes. Do not use tape between your toes as this can cause your skin to crack, which can lead to infection. Avoid lotions and creams that show alcohol as one of the first 3 main ingredients.

5. Nail care

Trim your nails horizontally without cutting off the edges. File your nails daily to reduce the frequency of trimming, but avoid scratching dry skin. If you have poor vision, have a family member do your nail care. If your nails are too thick or difficult to trim, consult your doctor.

6. Treatment of calluses and corns

Use a pumice stone or foot file to remove calluses while you are in the shower and your feet are still wet. If you have poor vision, have a family member help you. Do not use chemicals or strong antiseptics to remove corns or calluses, as this can cause burns. Do not remove corns. Some corns and calluses can only be removed professionally, especially if you have circulatory problems.

7. Stockings or socks

It is important for you to wear properly fitting socks or socks. Padded socks can help reduce pressure on your feet. Choose a pair of socks that are a mix of nylon and cotton. This material reduces friction on your skin. Do not wear repaired socks. Avoid stockings and socks that have elastic or garters and that have rips. Wash and change your socks or socks every day.

8. Wear shoes

Remember: Fashion is the enemy for those with diabetic foot neuropathy. Many serious foot problems are caused by pressure from shoes.

Avoid sandals with straps between the toes. Buy shoes that fit comfortably. Remember that not all shoes are one size fits all. Make sure the shoes are long enough and wide enough to give the toes enough room, especially if you have claw toes. Buy shoes in the afternoon when the foot is at its largest. Shoes should be comfortable when buying shoes, and do not rely on the stretch of the shoe. Shoes should be made of leather or fabric. Check your feet frequently when wearing new shoes, and do not wear new shoes for more than 1 hour on the first day. If you have neuropathy, significant foot deformities, or if you have had serious foot problems in the past, it is recommended that you consult an orthopedist or other professional to get your shoes fitted.

9. Your Responsibilities

Don't smoke, smoking reduces blood flow to your feet.

It is important to see your doctor regularly, making sure your feet and the area between your toes are examined at each visit.

Tell your foot and ankle surgeon that you have diabetes.

You should notify your foot and ankle surgeon when blisters or ulcers appear on your feet.

(Pictures from the Internet)