Diabetic foot syndrome
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Diabetic foot syndrome is a complex complication of diabetes involving ulceration, infection, or damage to deep tissues of the foot, typically arising as a result of diabetic neuropathy, impaired blood supply, and repetitive mechanical trauma. The loss of protective sensation means that an abrasion, blister, or foreign body in a shoe can remain unnoticed for a long time. Concurrent ischemia limits the delivery of oxygen, nutrients, and immune cells to damaged tissues. Diabetic foot syndrome requires interdisciplinary care because it can lead to chronic ulceration, bone infection, necrosis, and amputation. Early detection of changes, regular foot examinations, appropriate footwear, and professional care significantly reduce the risk of severe complications.
Diabetic foot syndrome - what is it
Diabetic foot syndrome is a clinical manifestation of several mutually exacerbating pathological processes. The most important of them is distal symmetric diabetic polyneuropathy, which is damage to peripheral nerve fibers associated, among other things, with chronic hyperglycemia, oxidative stress, microcirculation disorders, and metabolic changes in neurons.
Neuropathy may involve:
- sensory fibers, which leads to reduced perception of pain, temperature, pressure, and trauma;
- motor fibers, resulting in muscle atrophy, toe deformities, and abnormal pressure distribution;
- autonomic fibers, responsible for regulating sweating and microcirculation. Their damage promotes dry skin, cracking, and fissure formation.
The second primary mechanism is peripheral artery disease. Atherosclerotic narrowing of lower limb arteries reduces perfusion, or blood flow through tissues. In a person with diabetes, vascular changes often affect arteries below the knee and may present with few symptoms due to coexisting neuropathy. An ischemic wound heals more slowly and shows greater susceptibility to infection.
Foot deformities, limited joint mobility, calluses, poorly fitting footwear, injuries during nail trimming, and walking barefoot also contribute to the development of ulcers. A specific form of complication is Charcot neuro-osteoarthropathy, which involves inflammation, microfractures, joint destruction, and progressive foot deformity.
Treatment of diabetic foot syndrome depends on the clinical picture. It may include offloading the ulcer site, surgical wound debridement, infection treatment, restoration of arterial flow, glycemic control, and the selection of therapeutic footwear.
Diabetic foot syndrome - stages
Determining the stage of diabetic foot syndrome requires an assessment of wound depth, ischemia, infection, neuropathy, the extent of necrosis, and the location of the lesion. A single scale describes only some of these features; therefore, modern diagnostics utilizes several complementary systems.
The widely known Wagner classification includes the following grades:
- grade zero: the skin remains intact, but high-risk factors are present, such as deformity, callus, or a previous ulcer;
- grade one: superficial ulceration limited to the skin and subcutaneous tissue;
- grade two: the wound reaches a tendon, joint capsule, or other deep tissues;
- grade three: the deep ulceration is accompanied by an abscess, osteomyelitis, or joint infection;
- grade four: localized necrosis of part of the foot;
- grade five: extensive necrosis involving the entire foot.
The University of Texas classification combines the depth of the ulceration with the presence of infection and ischemia. As a result, it provides more accurate prognostic information than assessing wound depth alone.
The IWGDF and IDSA system is primarily used to classify infection:
- no clinical signs of infection;
- mild infection, limited to the skin and subcutaneous tissue;
- moderate infection, more extensive or involving deep tissues;
- severe infection with systemic inflammatory response features.
In the assessment of ischemia and amputation risk, the WIfI classification is used, which analyzes the wound, degree of ischemia, and severity of infection. In turn, the SINBAD system takes into account location, ischemia, neuropathy, bacterial infection, area, and ulcer depth. The classification is always carried out by qualified medical personnel, as the appearance of the wound surface may underestimate the true extent of the damage.
Diabetic foot syndrome - symptoms
The initial symptoms can be subtle. Neuropathy reduces the perception of pain, which is why advanced tissue damage is sometimes assessed by the patient as causing little discomfort. The absence of pain with a wound is therefore a possible sign of loss of protective sensation, rather than evidence of a mild course.
Symptoms of neuropathy include:
- numbness, tingling, and burning of the feet;
- an electric shock or prickling sensation;
- hypersensitivity to touch;
- diminished perception of temperature and pressure;
- balance disorders;
- dry, flaking, and cracking skin.
Local lesions may include calluses, corns, blisters, subkeratotic hematomas, cracked heels, ingrown toenails, and ulcers. A callus acts like a local foreign body: it increases pressure under the sole, promotes subcutaneous bleeding, and can precede the formation of a wound.
Signs of infection include redness, swelling, increased warmth, tenderness, purulent discharge, foul odor, and delayed healing. In people with neuropathy, ischemia, or reduced immunity, the inflammatory response may be less pronounced. Fever, chills, tachycardia, confusion, and marked weakness suggest a systemic infection.
Symptoms of ischemia include a cold, pale, or bluish foot, loss of hair, shiny skin, diminished pulses in the foot arteries, pain when walking, and rest pain. Neuropathy can mask pain.
Urgent medical evaluation is required especially for:
- a new wound, blister, or bleeding under a callus;
- rapidly worsening redness or swelling;
- black, bluish, or rapidly blanching tissues;
- oozing of purulent discharge;
- visible bone or a deep fissure;
- a suddenly hot, swollen, and red foot, especially with little pain;
- systemic symptoms accompanying a foot lesion.
Diabetic foot syndrome - prevention
Prevention begins with regular risk assessment. The examination should include the condition of the skin and nails, the presence of deformities, protective sensation, and blood supply. Sensation is assessed, among other methods, using a ten-gram monofilament, as well as through vibration sensation testing. Circulation assessment includes pulse examination and, depending on indications, vascular tests. Arterial wall calcification may falsely elevate the ankle-brachial index, which is why results are interpreted together with the clinical picture and other perfusion measurements.
Basic preventive measures include:
- daily inspection of the entire surface of the feet, interdigital spaces, and nails;
- using a mirror or the assistance of another person in case of limited mobility;
- daily washing of the feet in lukewarm water and thorough drying;
- applying an emollient to dry skin, avoiding the spaces between the toes;
- daily changing of socks to non-constrictive ones made of moisture-reducing material;
- checking the inside of footwear before putting it on;
- wearing sufficiently wide shoes of the proper length and with a stable sole;
- gradually getting the feet used to new footwear;
- regular physical activity tailored to the condition of the feet and the circulatory system;
- control of blood glucose levels, blood pressure, and lipid disorders;
- smoking cessation.
Corns, calluses, and nails requiring specialized care should be entrusted to a podiatrist working in cooperation with a physician. Self-use of blades, rasps, rotary tools, and keratolytic preparations with high acid concentrations increases the risk of skin damage. Hot water bottles, heating pads, and hot baths can cause burns when temperature sensation is impaired.
The frequency of follow-up visits depends on the risk category. A person with a history of an ulcer, amputation, or with advanced neuropathy and arterial disease requires significantly more frequent check-ups than a patient with intact sensation and normal blood supply.
Diabetic foot syndrome - podiatric care
A podiatrist is primarily involved in prevention, early detection of lesions, and safe foot care. The visit should begin with a medical history regarding diabetes, prior ulcerations, amputations, vascular diseases, neuropathy, medications taken, and daily care routine. Next, the skin, nails, interdigital spaces, deformities, footwear, and areas of excessive pressure are assessed.
The scope of professional care may include:
- atraumatic shortening and preparation of nails;
- cleansing of the nail folds;
- controlled removal of calluses and corns;
- care of dry, hyperkeratotic, and cracked skin;
- selection of home care products;
- education regarding hygiene, footwear, and daily self-examination;
- application of protective offloading after biomechanical assessment;
- referral to a physician upon suspicion of ulceration, infection, ischemia, or Charcot foot.
The procedure should be performed aseptically, using sterilized instruments and techniques that minimize the risk of skin cuts. Intensive abrasion of the epidermis, aggressive excision of calluses, soaking feet in hot water, and strongly warming treatments increase the risk of complications.
An active ulcer requires management by a diabetic foot care team. In such cases, wound offloading, vascular assessment, infection control, debridement of necrotic tissue, and metabolic control are of key importance.
