Diabetic foot: How can you prevent wounds?

Our feet usually have a good blood supply and are very sensitive. There are a lot of nerves in the skin that react to the slightest pressure and touch. For instance, most people will notice a small stone in their shoe right away. This may be different in people who have diabetes: Constantly high blood sugar levels often lead to

• nerve damage (neuropathy): If nerves in the feet are damaged, sore areas and small injuries may be less noticeable or even not felt at all.
• damage to the blood vessels (macroangiopathy): This reduces the blood supply to the feet and it takes longer for wounds to heal.

Smoking, high blood pressure and lack of movement can make blood vessel damage worse, reducing the blood supply to the legs and feet even more.

If nerves and blood vessels in the feet are damaged, even minor injuries like cuts or scrapes can easily turn into poorly healing wounds (chronic wounds). They can develop as a result of

• wearing shoes that are too tight: This can easily lead to rubbing, pinched skin and blisters.
• foot deformities: Bunions (hallux valgus), hammer toes and claw toes can lead to sore areas.
• thick, hard skin (calluses).

The signs of diabetic foot problems differ depending on whether they are mainly caused by nerve damage or blood vessel damage.

Symptoms caused by nerve damage:

• The foot becomes less sensitive to pain, pressure, heat and cold.
• The foot feels numb (“like walking on cotton”).
• The foot tingles ("pins and needles").
• The skin is very dry and warm.
• Poorly healing wounds develop, particularly on the sole of the foot.

Symptoms caused by blood vessel damage:

• The foot feels cold.
• The skin is pale or blue.
• Walking leads to pain in the calves (lower legs) – but this symptom doesn't occur if there is nerve damage too.
• You can hardly feel a pulse in the feet.
• Open wounds develop, usually on the toes or heel.

The doctor

• examines the skin and checks whether the foot feels cold or warm,
• checks for wounds, sore-looking areas and deformities,
• sees how deep a wound is and whether it is infected,
• looks for signs of poor blood supply to the foot and
• tests how sensitive the nerves are by touching the feet with a tuning fork or a light nylon thread.

An ultrasound or angiography can be done to find out how good the blood flow is in the legs. Imaging techniques (x-ray exams, CT scans or MRI scans) can be done to see whether any bones have been damaged too.

If diabetic foot problems aren't discovered and treated early enough, chronic wounds (ulcers) may develop. They usually develop on the toes, sole of the foot, heel or ankle. Diabetic foot ulcers can become very deep and infected. Black areas in the wound are usually a sign that tissue has died. If the ulcer becomes very large, deep and infected, the toe or part of the foot may have to be removed (amputated).

People often don’t realize how dangerous wounds or injuries could become because the nerve damage prevents them from feeling much (or any) pain. As a result, many don't give the wounds the attention and care they need.

Charcot foot is a rare type of diabetic foot problem. The nerve damage is so severe that people don't even notice broken bones in their foot. It can lead to foot deformities, injury-prone skin and ulcers. The early signs of Charcot foot include redness, swelling and heat.

Some people have trouble recognizing diabetic foot problems themselves. There are various reasons for this:

• The nerve damage prevents them from feeling any (or much) pain in their feet. As a result, they often don't notice injuries or wounds on their feet. Or they don't notice that their shoes are too tight.
• Many can’t see their feet very well because their vision has got worse due to their diabetes or age.
• They can't bend or move their body enough to be able to examine their feet closely.

Because of this, it's very important to

• regularly have your feet examined by a doctor,
• keep an eye on your feet yourself too, if possible, and
• take wounds and sore-looking areas seriously, no matter how small they are.

It can be helpful to use a hand mirror to look at the soles of your feet. If that’s still difficult, though, you can ask a friend, family member or caregiver to check your feet regularly. Going to a podiatrist for professional foot care can help to recognize problems in time too.

There are a number of things you can do to make sure your feet stay healthy despite having diabetes. The main ones are:

• Controlling your blood sugar levels: Keeping your blood sugar levels down can prevent damage to the nerves and blood vessels. People who have type 1 diabetes need treatment with insulin to do this. In type 2 diabetes, changing your diet and getting more exercise is often enough to lower your blood sugar levels. Tablets (antidiabetics) or special injections (containing incretin mimetics) can be used as well. If these treatments aren't effective enough, people who have type 2 diabetes might have to use insulin too.
• Reducing pressure on your feet: This prevents wounds from developing. It is important to wear shoes that fit properly and aren’t too tight. Your feet should be checked and measured to be sure.
• Avoiding injuries: People who have a higher risk of chronic wounds shouldn’t walk barefoot, for instance – even at home.
• Foot care: Care for your feet and inspect them every day. People who are close to you could also help here. Professional foot care can be a good idea too.
• Going to the doctor for regular check-ups: The doctor will examine your feet and ask about symptoms like pain or numbness.

It is very important to see a doctor soon if you notice anything unusual. Even minor injuries and areas of sore-looking skin should be taken seriously.

High blood pressure and high blood lipids (high blood fats) further increase the risk of nerve and blood vessel damage. So it can also be important to treat these medical problems. Giving up smoking lowers the risk of developing them, too.

It is very important to prevent the skin on your feet from becoming vulnerable to damage and injury. One way to do this is by wearing shoes that

• are long enough, wide enough and high enough so they don't pinch your feet. You should be able to move your toes easily and freely.
• are well cushioned.
• do not have bothersome stitching on the inside (e.g. in the lining or straps) that could rub against your feet.

Custom orthopedic shoes and insoles can sometimes be a good idea too.

It is important to check for – and remove – things like sand or stones in your shoes before putting them on. You should also repair or replace worn-out shoes.

In people who have a foot deformity, surgery can be done to reduce the pressure on certain parts of the foot.

You can do the following to protect your feet from injury:

• Do not walk barefoot. Wear comfortable shoes instead.
• Wear seamless socks. You should change your socks every day.
• Do not use nail scissors to cut your toenails because you could easily cut your skin by accident. It is better to file your toenails instead – in a straight line so they don't grow into the skin (become “ingrown”).
• Do not have hot foot baths. They can damage the skin. This is also true for other sources of heat, such as hot water bottles or electric blankets.

If the skin on your foot is injured, red or irritated despite doing these things, you should show it to your doctor. This is also true for small cuts or scrapes.

Good foot care involves

• washing your feet every day with lukewarm water and drying them properly afterwards, particularly the spaces between the toes.
• moisturizing your feet with a cream, foam or lotion that has 5 to 10% urea in it. Do not use greasy ointments, oils or zinc pastes!
• avoiding or treating fungal foot infections (athlete's foot).
• regularly filing your toenails in a straight line.
• carefully removing calluses (thick, hard skin) with a pumice stone.
• checking your feet for redness, irritation, injuries, athlete's foot or other abnormal areas – every day, if possible. It can be difficult to see the whole of your foot, including the sole of the foot and the spaces between your toes. Using a hand mirror can help here.

If you're unable to take good care of your feet yourself, you will need support – for instance, from your family or close friends. In Germany, statutory health insurers cover the costs of professional medical foot care if you have a high risk of developing chronic wounds.

Disease management programs (DMPs) are structured treatment programs that aim to improve the management of chronic illnesses. They include regular doctor's appointments where you talk with the doctor and he or she examines you. You can also take part in things like patient education classes. DMPs for people who have diabetes offer many advantages that can improve the treatment, so it’s worth taking part in one.

The aim is to avoid possible long-term problems caused by diabetes, such as diabetic foot problems. So the diabetes DMP in Germany includes

• regular foot examinations by a doctor (every 1 to 12 months, depending on the findings of the last examination),
• advice about appropriate footwear,
• prescriptions for medical foot care, and
• referrals to diabetic foot specialists if wounds develop on the feet.

The treatment is usually coordinated by your family doctor, and sometimes by a diabetologist (diabetes specialist).