Care of the foot in diabetes
How diabetes can damage your feet
Diabetes affects the blood circulation and nerves in your feet. Good circulation is necessary to keep the nerves and muscles inside your foot healthy, as well as the skin that encases it.
Diabetic neuropathy, which involves damage to the nerves and loss of sensation in the extremities of the body, is the condition that robs the feet of normal feeling and deadens the pain reflex. Therefore, if you had a puncture wound on the sole of your foot, you would not be aware of it.
Unless you examined your foot you would not realise that anything was amiss. This makes regular foot checks very important for people with diabetes.
Your foot health should be checked at least once a year by a healthcare professional but you are recommended to undertake daily foot checks yourself and to contact your GP if you have any concerns. You should be looking out for cuts, blisters, corns, calluses, burns or any problems with toenails, as well as any changes in skin temperature or colour.
Diabetes weakens the muscles in the foot and this results in undue pressure being placed on the skin at the soles of your feet. While the skin is normally a barrier to infection, with diabetes open foot ulcers can easily develop from blisters and small wounds.
Due to the effects of high or fluctuating blood sugar levels, they may be slow to heal and need ongoing treatment to cure them. They have the potential to develop into serious lower body infections, such as osteomyelitis, and need to receive treatment at the earliest possible stage.
Ulcers can be caused by treading on something sharp, wearing ill-fitting shoes, or they may develop from blisters or other minor trauma. Reduced blood flow to the foot can impede the healing process and leave it prone to further infection.
Severe diabetic neuropathy can affect both your sensation and your sense of balance, resulting in fractures or deformities in the bones of your foot and leading to a condition called Charcot foot. This causes swelling or redness of your foot or ankle, as well as a deep aching and warmth in the skin at the point of injury. If it does not receive prompt attention, it can result in the formation of ulcers.
Treatment consists of reducing pressure on your foot and wearing a plaster cast to allow it to set and heal in the correct position. During this period of healing, you will need to check the condition of your other foot, which will be under more pressure as it is having extra load put on it.
While the information above may seem daunting, it is important to stress that, once diabetic peripheral neuropathy or peripheral arterial disease are diagnosed and treated, foot ulcers and other complications are preventable.
Personal vigilance and timely medical or surgical intervention are key to good management of the risks attached to diabetes.
Surgical management of diabetic foot conditions
Surgical treatment is of benefit when patients with Charcot foot or ankle have not been helped sufficiently by treatment with a pressure-reducing cast aimed at offloading. It is indicated when a deformity puts the foot at risk of ulceration and when it cannot be safely protected in specially adapted footwear. However, if acute inflammation is present, conservative treatment may need to continue until this is brought under control.
Infections from the foot can spread up the leg and block small arteries, cutting off much of the blood supply. Revascularisation may well be needed to save the limb in serious cases of infection and diabetic foot surgery requires the expertise of a vascular surgeon to ensure an optimal outcome.
The surgery itself may be undertaken by a specialist in orthopaedic, vascular or general surgery who will be well versed in the behaviour of infections, as well as in wound management and the biomechanics of the foot.
Chronic osteomyelitis is a serious bone infection to which diabetics are particularly prone. It frequently affects the long bones of the leg and invariably requires surgical treatment before the commencement of antibiotics, as surgical debridement removes the infected fragments of bone that are beyond the scope of antibiotics.
Potential risks following surgery
The risk of wound infection, excessive bleeding or tissue damage is a consideration of all surgery but, in the presence of diabetes, the risk is significantly higher.
High sugar levels in the blood prior to surgery or following it pose a risk to wound healing due to the danger of dehiscence, or rupture, along the site of the surgical incision. As well as delaying healing, already slowed where diabetes is a factor, this can lead to infection and require prompt intervention.
Since nerve damage can mask the pain caused by an infection, it is important to be on the lookout for signs, such as redness or excessive drainage from the wound.
The impaired blood supply, often associated with diabetes can cause ischaemia, resulting in tissue death and compromising the healing process of the surgical wound.
Following any surgery, another serious and possibly life-threatening complication is sepsis, where the body's response to bacterial infection results in injury to its own tissues and organs. Symptoms of sepsis include fever, accelerated heart and breathing rates and confusion.
Working towards an optimal outcome
Best practice in the care of people with diabetic foot conditions consists in co-operation between both the medical and surgical disciplines. A combination of antibiotics and surgery is indicated in many foot infections, although some can be medically managed without recourse to surgery.
Successful treatment - which requires a thorough understanding of the various factors leading to foot infection in diabetic patients and how best to care for them - clearly benefits from a multidisciplinary approach.
People with diabetes are cared for mostly in the community - by their GPs, specialist nurses and in diabetic foot clinics, all of whom can make referrals to hospital as and when necessary. It is important that patients are proactive in their own care and that they quickly raise any concerns with their healthcare providers in the community.
Speed is of the essence in securing a successful outcome to treatment, whether medical or surgical.
As already mentioned, regular self-examination of your feet is very important. It is advisable not to walk barefoot, even at home, to avoid the risk of injury. Choosing the right footwear is also important, as ill-fitting shoes can be particularly damaging to your feet in the presence of diabetes.
Lifestyle changes where necessary, such as quitting smoking, becoming a â€œlabel readerâ€ to ensure healthy eating, achieving and maintaining the right weight and so on, are of benefit to everyone but they are of particular benefit where diabetes is concerned.
In terms of diet, saturated fat is known to raise the levels of sugar in the blood and to cause poor insulin regulation, while dietary fibre, especially that contained in fruits and vegetables, has been found to result in lower blood sugar levels.
The dangers of smoking are well known. In relation to diabetes, smoking raises the risk of heart and kidney disease, as well as further restricting the flow of blood in the legs and feet and heightening the risk of infection and ulcers.
Diabetes benefits from scrupulous management. The need for vigilance and compliance with your prescribed drug regime and other professional advice cannot be over-emphasised.