Foot care problems
This article explains the increased risks that diabetics run and some common footcare problems they may experience. Proper footcare is essential for diabetics and any problems should be treated by a specialist - never with over the counter remedies.
Without continuous good metabolic control addressing hyperglycaemia, hypertension, hyperlipidaemia and use of tobacco products, diabetic patients may develop damage to peripheral nerves and blood vessels and become prone to ulcers, severe foot infections and gangrene.
Neuropathy
Nerve damage, or neuropathy, is a common complication of diabetes, and results in loss of protective pain sensation in a stocking distribution covering the feet and lower legs.
Without protective pain sensation, patients may not be aware when they injure the foot or develop an infection.
Autonomic neuropathy renders the skin of the feet dry and prone to splits or fissures, through which infection can enter the foot.
Some patients develop a motor neuropathy, leading to muscular imbalance in the foot and a characteristic deformity - clawing of the toes and raising of the arch of the foot, causing high pressure points on the sole of the foot.
Hyperkeratosis (callus) develops on sites of high pressure, and leads to ulceration. The neuropathic ulcer is found on the sole of the foot and is painless so the patient continues to walk without limping and the ulcer cannot heal.
Ischaemia
In addition to neuropathy, patients with poor metabolic control are liable to develop ischaemia, which usually affects the blood vessels below the knee.
When the blood supply to the foot is poor, ulcers are slow to heal and prone to become infected. Ischaemic ulcers develop around the margins of the foot and are often associated with pressure from tight shoes.
Infection
To fight infection and heal foot ulcers, the patient needs to mount an inflammatory response but this depends on the nervous and vascular systems being intact.
In the presence of neuropathy and ischaemia, inflammation is diminished, and infection can spread with alarming rapidity.
The usual signs and symptoms of infection, namely redness, swelling, pain and purulent discharge, may be less evident in diabetic feet, and fever and leucocytosis may be absent even in patients with severe infections.
Screening
In order to detect foot problems early and prevent amputations, diabetic patients should be screened for neuropathy and ischaemia, the presence of which will render them at high risk of developing ulceration.
High-risk patients should be taught to check their feet every day for the presence of foot problems. Elderly patients who cannot reach their feet or have impaired vision will need help with the foot check.
Danger signs
The danger signs of impending - or actual - foot problems include swelling, colour change, pain or throbbing, or an open sore on a foot or part of a foot.
All diabetic patients should be aware of these danger signs and should be taught to seek professional help immediately a problem arises, instead of undertaking self-treatment with over the counter remedies.
In particular, diabetic patients should be warned that even though a problem may not be painful, it can still be very serious and need help from an expert. Just as there is no such thing as mild diabetes, there is no such thing as a trivial diabetic foot lesion.
Self-treatment danger
In general, diabetic patients should be discouraged from self-diagnosis and from using over-the-counter remedies because using them may result in delay in reporting of the problem and receiving appropriate treatment.
It is difficult for a lay person to assess the potential severity of a diabetic foot problem, and many amputations begin with a small defect in the skin which appears trivial, such as a blister or an in-growing toe nail which is neglected or given inappropriate care.
Corns and calluses on the diabetic foot are often the precursors of neuropathic ulceration. They always need expert treatment, which will involve pressure off-loading as well as debridement of the corn or callus.
Some proprietary corn and callus remedies contain strong acids which can result in extensive tissue necrosis - they should never be used by diabetic patients.
In-growing toe nails need the spike of nail at the edge of the nail plate removed.
Footwear and footcare
All diabetic patients should know what sort of shoes are suitable for everyday use and for occasions when they will be standing and walking for long periods of time.
Such footwear should be sufficiently broad, long and deep, to avoid pressure on the toes. Heels should be less than two inches high, and shoes should fasten high on the foot with a lace or strap.
Socks should be changed every day and should be loose-fitting and without prominent seams. Patients with neuropathy should not walk barefoot or use hot-water bottles.
Patients should have a daily footcare routine. The feet should be washed with warm water and mild soap and dried carefully. An emollient such as E45 cream should be rubbed gently into areas of dry skin.
The nails should be cut straight across, or in a gentle curve following the line of the end of the toe and should not be allowed to grow too long. If the nails are painful or thickened, the diabetic patient should seek the help of a State Registered chiropodist/podiatrist (which should be available without charge to the patient at National Health Service clinics).
Other common foot problems such as corns, calluses, in-growing toenails, chilblains and verruca pedis are within the scope of community podiatrists.
However, diabetic patients with large blisters, ulcers, infections or sudden onset of pain should be seen urgently in the diabetic foot clinic.
Diabetic foot ulcers
Diabetic foot ulcers, both neuropathic and ischaemic, need multi- disciplinary care from a dedicated team including physician, chiropodist, nurse, orthotist and surgeon.
Ulcers need sharp debridement to remove associated callus and non- viable tissue, and application of non-adherent sterile dressings which are changed daily for wound inspection.
Pressure off-loading, with special shoes, insoles or casts, is essential, as is infection control with wound swabs sent for microscopy and culture and antibiotics to control infection.
Antibiotics can be continued for longer periods than for non-diabetics. Ischaemic patients may benefit from angioplasty or bypass to improve perfusion of the foot. Good diabetes management and control of the `great quartet' of hyperglycaemia, hypertension, hyperlipidaemia and smoking will improve outcomes for diabetic foot patients.
Above all, education in preventive footcare, early detection and early reporting of problems, and techniques for achieving rapid healing should be given to all diabetic foot ulcer patients.
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