Diabetic Foot Ulcers and Their Treatment

Why diabetes leads to foot ulcers

Diabetes damages the foot from two directions at once — through the nerves and through the arteries — and an ulcer usually appears where those two problems meet. Years of raised blood glucose injure the small sensory nerves first. As they fail, the foot goes numb, or tingles, or simply stops reporting what is happening to it. Pain is a protective signal: a shoe that rubs, a sock seam pressing on a toe, a stone that has found its way inside a sandal all hurt, and someone with normal sensation reacts within minutes. Once that signal is gone, the pressure carries on unnoticed for hours and the skin breaks down. Most diabetic foot ulcers begin exactly this way — silently.

Nerve damage does more than remove pain. Sweating decreases, so the skin dries and cracks. The small muscles that balance the toes weaken, the toes claw, the bones of the forefoot become prominent, and body weight concentrates on a few small points. In many patients an arterial problem is layered on top: narrowed leg arteries reduce the blood reaching the wound, and with it the oxygen, the cells needed for healing, and any antibiotic given to treat infection. Add the blunting effect of high glucose on the immune response, and a graze that would heal within a week on a healthy foot can stay open for months and travel deeper instead.

• Long-standing diabetes with poorly controlled blood glucose
• Numbness, tingling or loss of sensation in the feet (neuropathy)
• Peripheral arterial disease and smoking
• A previous foot ulcer or toe amputation
• Toe or forefoot deformity and heavy callus
• Kidney failure, poor eyesight, or anything that makes reaching the feet difficult

Signs that need to be seen the same day

Timing matters more in diabetic foot infection than in almost any other wound. Infection can travel along tendon sheaths surprisingly quickly, and a small break in the skin may sit above a much larger collection of pus. In a foot that has lost sensation, none of this necessarily hurts. Assuming a painless wound is not urgent is the most costly mistake in diabetic foot care — the absence of pain is not reassurance.

If any of the following are present, the foot should be examined that day rather than at the next scheduled appointment. Fever, feeling generally unwell, or blood glucose that suddenly becomes hard to control can all be the body responding to infection, and are reason enough to have the foot looked at even when the wound itself appears unchanged. For anyone caring for a relative at home, the practical rule is simple: if something is there today that was not there yesterday, it does not wait until tomorrow.

• Redness spreading out from the wound, with warmth or firmness
• Sudden swelling of the foot
• Foul smell or purulent discharge from the wound
• Tissue turning dark or an area of blackened skin
• Fever, shivering or general malaise
• An unexplained rise in blood glucose

Daily foot checks, footwear and prevention

A large share of diabetic foot ulcers is preventable, and most of that prevention happens at home — carried out by the patient or by a family member. The foundation is checking the feet every day. The whole foot needs to be seen, including between the toes, the heel and the sole; if bending or seeing is difficult, use a hand mirror or ask a relative to make it a routine task. Wash with lukewarm water, dry carefully between the toes, and apply moisturiser to the skin but not in the toe webs. Test water temperature with an elbow or a thermometer rather than a hand that may itself be numb.

Footwear is part of the treatment, not a matter of taste. Shoes should have a wide toe box, should not squeeze the foot, and should have no internal seam pressing on the skin; new shoes are broken in over a few hours a day. Feel inside the shoe with your hand before putting it on, and do not walk barefoot, even indoors. Cut nails straight across without digging into the corners. Calluses and hard skin should never be pared at home with a blade, a sharp file or a medicated corn plaster — these attempts frequently create the ulcer in the first place. In a foot with reduced sensation, hot water bottles, heaters and open fires carry a real risk of burns that will not be felt.

• Inspect the whole foot daily, including between the toes
• Feel inside each shoe with your hand before putting it on
• Never walk barefoot, even at home
• Cut nails straight across; do not cut calluses or use corn plasters
• Wear seam-free, non-constricting socks and change them daily
• Keep away from hot water bottles, heaters and direct heat

Assessing the wound and the circulation

Examination records the site, size and depth of the ulcer, and a sterile probe is used to establish whether tendon, joint or bone lies beneath it. A wound that probes to bone raises the question of osteomyelitis, which is investigated with plain X-rays and, where needed, MRI. If infection is suspected, a culture taken from a surface swab tells you little; a specimen from the debrided wound base or from deep tissue is what allows antibiotics to be directed at the organism that is actually there.

The second half of the assessment is circulation. Foot pulses are checked by hand, and where there is any doubt an ankle-brachial pressure index, duplex ultrasound and, if indicated, angiographic imaging are arranged. This distinction is decisive, because if arterial inflow is inadequate no dressing and no antibiotic will be enough on its own — restoring blood flow (revascularisation) has to come first, and vascular opinion is sought at that point. Glycaemic control, kidney function and nutritional state form part of the same picture. At İzmir Cerrahi Merkezi the assessment is made as a whole, working alongside endocrinology, vascular surgery and infectious diseases input where the case calls for it.

Debridement, offloading and infection control

Treatment begins with removing dead and infected tissue. Debridement gives the ulcer a living base to heal from, and it is rarely a one-off: it may be repeated at intervals until the wound closes. Limited debridement can often be done in clinic under local anaesthesia, while a deep abscess, infection tracking along a tendon, or bone involvement calls for the operating theatre. Where pus has collected in a closed space, draining it comes before antibiotics rather than after — an antibiotic cannot reach far into an undrained collection. Antibiotic therapy is then guided by culture, and its duration depends on how deep the infection has gone.

The second step is the one most often neglected: offloading. A plantar ulcer that continues to be walked on will struggle to heal no matter how meticulous the dressing regimen. Depending on where the wound sits, this may mean a total contact cast, a removable walker boot, a bespoke insole, crutches or a wheelchair; for some patients a period of bed rest is needed. The dressing itself, contrary to what most people expect, is not the decisive variable. It is chosen to balance moisture at the wound base and protect the surrounding intact skin, and it is changed as the wound changes. Diabetic foot care is, in short, a service — debridement, circulation, infection control, offloading and glucose management run together and reviewed regularly.

Protecting the limb and staying in follow-up

The aim of treatment is to close the wound and keep a functional foot. Coming in early is the strongest tool for achieving that: clearing infection before it goes deep, restoring blood flow, and taking weight off the ulcer usually make it possible to achieve healing with more limited intervention. In some situations removing a single toe or a small part of the foot becomes necessary; this is done to preserve the rest of the foot and the ability to walk, and it is decided in detail with the patient. What timely care is working to avoid is loss at a higher level — we say this plainly, not to alarm anyone, but because it explains why delay matters.

Follow-up continues after the wound has closed, because the pressure points and the underlying nerve and vessel changes are still there. Suitable footwear and insoles, daily inspection, steady glucose control and periodic foot examination are the continuation of treatment, not an optional extra. If you have a foot wound that is not healing, a change in colour, new numbness or unexplained swelling, our surgeons at İzmir Cerrahi Merkezi can examine you and talk through a plan for your situation. Every patient's circulation, infection and general health differ, so any treatment decision can only be made after examination and the necessary investigations.