Diabetic foot ulcers

Overview – diabetic ulcers are found on the foot

We all get wounds on our feet, sometimes from shoes that have rubbed or by injuring our feet in some other way.

If you know you have diabetes and you have a wound on your foot, then you should seek advice from your healthcare professional urgently (ie within 1 day). If your wound is taking longer to heal or there are no signs of healing, it might be a sign of an underlying problem that needs investigating further.

If you have a non-healing wound on your foot, it is possible this may be caused by peripheral arterial disease (poor circulation), which is a known complication of diabetes and heart disease. 

Diabetes can also cause loss of sensation (neuropathy) so you may not notice when you injure your feet as you can not feel pain.  Skin damage to the feet, resulting in a wound, can also be caused by trauma, or friction.

Less commonly, wounds on the feet can also be caused by venous disease or rarer causes of ulceration such as skin cancers.

Symptoms – what are the typical symptoms of diabetic foot ulcers?

What do diabetic foot ulcers look like?

Causes – what can cause diabetic foot ulcers?

Peripheral arterial disease

Reduced blood flow to the foot means the skin can become thinner and weaker, and more prone to damage from rubbing or friction. Any break in the skin can then develop into an ulcer. One cause of poor healing in the lower leg is when not enough blood is getting to our feet. Blood travels from our heart to our feet through our arteries. If our arteries become too narrow, our skin will not get enough blood to allow the wound to heal as normal.

Arteries can become ‘furred’ up by the build-up of fibrous and fatty material inside the arteries (atherosclerosis). Atherosclerosis is the underlying condition that causes heart disease such as heart attacks and strokes as well as affecting the arteries that supply the legs. This is called peripheral arterial disease.

You can read more about peripheral arterial disease on NHS Choices and on the British Heart Foundation website.

Diabetes

Peripheral arterial disease is a known complication of diabetes. You can read more about peripheral arterial disease and diabetes on NHS Choices and on the Diabetes UK website.

Diabetes can also cause loss of sensation (neuropathy) so you may not notice when you injure your foot because you cannot feel the pain.

Diagnosis – getting diagnosed with a diabetic foot ulcer

Making an appointment

If you have a wound on your foot that is not healing, make an appointment at your GP practice or with a podiatrist. You may be given an appointment to see the nurse rather than the doctor as they (and podiatrists) are often responsible for caring for patients with leg and foot problems.

If you know you have diabetes and you have a wound on your foot, then you should seek advice from your healthcare professional urgently (ie within 1 day).

Make sure you remove any nail polish from your toenails before your appointment.

When you see the nurse, podiatrist or doctor, they should:

• Ask about your symptoms and how long you have had problems
• Examine your lower legs and feet
• Check your circulation by palpating your pulses, listening to your pulses with a Doppler. They may also take pressures around your arm, ankle and toe.  This test compares blood flow to find out if there are circulation problems in your lower leg. You may have to come back to have your Doppler test on another day or at another clinic but if this test is required, you should have this test within a few weeks of your first appointment
• Test whether you have any loss of sensation in your feet

You might also be offered some more tests to rule out other health problems that can affect your legs and feet, including diabetes, anaemia, thyroid, kidney and cholesterol problems.

If your GP practice thinks you have problems with your arteries, they may refer you for further vascular tests at your local hospital or specialist clinic.

What to expect at your appointment

Most people with a non-healing foot wound need to be urgently referred to a podiatrist who will act as the gatekeeper to the wider multidisciplinary team.

You should have an initial assessment that includes an examination of both feet to look for evidence of:

• Neuropathy – use a 10g monofilament as part of a foot sensory examination
• Assessment of circulation to review limb ischaemia (see the NICE guideline on lower limb peripheral arterial disease)
• Ulceration
• Callus
• Infection and / or inflammation
• Deformity
• Gangrene
• Charcot arthropathy
• Medication such as Amlodopine, Hydroxyurea, Nicorandil to treat
• Schleroderma
• Venous disease and Atrophie Blanche in particular

If you need to have further assessment, this should include:

• Doppler assessment of ankle brachial pressure index and / or toe pressures
• X-rays or other scans to determine any deep tissue (e.g. bone) involvement
• Microbial culture
• Gait analysis which includes looking at the way you walk
• Pressure mapping

Treatment – how do you treat a diabetic foot ulcer?

Referral options for diabetic foot ulcers

You should be referred to a specialist podiatrist and / or vascular service to look into why your diabetic foot ulcer is not healing. Treatment should include these six main components for any foot-related wound to optimise the chance of wound healing:

• Management of the underlying condition or cause e.g. control of diabetes, optimising blood flow, management of the oedema etc.
• Debridement of the wound. This is the removal of material from within and around the wound such as slough, biofilm and callus which can impede wound healing.
• Good management of wound symptoms through appropriate dressing selection or adjunctive therapies.
• Managing infection and bioburden and prevent
• Offloading or deflecting pressure away from the wound. This may involve shoe adaptations, inserts and often casted devices are required.
• Compression therapy where peripheral arterial disease has been excluded. This may include the need for toe garments

Diabetic foot wounds have a particularly high recurrence rate of around 40% at one year and up to 75% by year five. It is therefore more helpful to think of a diabetic foot ulcer as being in ‘remission’ rather than ‘healed’

Appropriate footware and podiatry visits

If you have suffered a chronic foot wound, you should be placed into a protective foot care programme. It’s also important that you have regular podiatry visits, footwear and orthotic reviews and that the risk factors such as diabetes are kept under control.

If you have diabetes or peripheral arterial disease and a foot wound, you are at increased risk of cardiovascular incidents such as stroke and heart attack and should have your cardio-vascular risks modified.

Outlook

Up to seven in 10 venous ulcers heal within 12 weeks if treated with compression bandaging which is reapplied every week or so. If compression is not used and an ordinary dressing or support (compression) stockings alone are used, the chance of healing is less.

Resources

1. Diabetes UK (Web page)
2. Top tips for foot care (PDF download)
3. Tips on choosing the right footwear (Web page)

Clinical guidelines for foot ulcers

• NICE Peripheral Arterial Disease Diagnosis and management (Web page)
• NICE Guidelines for the prevention and management of the Diabetic foot (Web page)
• Scottish intercollegiate guidelines on diabetes (PDF download)
• Best practice guidelines. Wound management of diabetic foot ulcers (PDF download)
• Local management of diabetic foot ulcers (PDF download)

Research

1. The Cochrane Library publishes systematic reviews about the effectiveness of many treatments for diabetic foot ulcers and summarises this in a useful
2. ‘Evidently Cochrane’ paper (Web page)