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Diabetes remains a major global health challenge, driving significant morbidity, mortality, and economic strain. Among its many complications, diabetic foot ulcers represent one of the most disabling and life-threatening outcomes, affecting up to one-third of individuals with diabetes and serving as the leading cause of nontraumatic lower-limb amputations worldwide. This course reviews ulcers arising from a complex interplay of neuropathy, peripheral arterial disease, and impaired wound healing, often worsened by infection, as well as discusses how foot ulceration, beyond localized tissue damage, reflects systemic vascular compromise and sharply increases cardiovascular mortality. This activity explores the evaluation, classification, and effective management of diabetic foot ulcers, including interprofessional strategies that encompass offloading, infection control, vascular assessment, surgical intervention, and optimization of glycemic and comorbid conditions. Participants will also gain an understanding of diagnostic accuracy and risk stratification. This activity for healthcare professionals is designed to enhance the learner's competence in identifying diabetic foot ulcers, performing the recommended evaluation, and implementing an appropriate interprofessional approach when managing this condition, ultimately promoting limb preservation, accelerating wound healing, and improving long-term patient outcomes. Objectives: Identify the pathophysiologic mechanisms of diabetic foot ulcers. Assess ulcer characteristics using validated diagnostic classification systems. Implement evidence-based management of foot ulcer complications in patients with diabetes mellitus. Collaborate with interprofessional team members in the coordinated management of diabetic foot ulcers to improve patient outcomes. Access free multiple choice questions on this topic.

Diabetes mellitus poses a major global health challenge, contributing substantially to morbidity, mortality, and economic strain. In addition to acute and chronic complications, diabetic foot ulcers cause significant disability and loss of quality of life while contributing heavily to overall morbidity and mortality. As many as one-third of individuals with diabetes develop foot ulcers during their lifetime, making this condition the leading cause of atraumatic lower extremity amputations worldwide.[1][2] Foot ulcers in patients with diabetes arise from a complex interaction of peripheral neuropathy, peripheral arterial disease (PAD), and impaired wound healing, frequently exacerbated by infection.[3] Beyond localized tissue damage, diabetic foot ulceration reflects widespread systemic vascular disease and heightens the risk of cardiovascular morbidity and premature mortality.[4][5] Major lower extremity amputation is associated with significant morbidity and mortality, with postamputation 5-year mortality rates exceeding 50% in patients with diabetes.[6] Several factors predict poor outcomes in individuals with diabetic foot ulcers, including ulcer severity, prolonged duration, infection, PAD, neuropathy, chronic kidney disease, cardiovascular disease, smoking, and male gender. These variables influence healing rates, recurrence, and the likelihood of progression to major amputation and death.[1][7][8][9][10] Effective management of diabetic foot ulcers and their complications demands a comprehensive, evidence-based strategy. Essential interventions include pressure offloading, infection control, revascularization, surgical intervention, glycemic control optimization, and management of comorbidities. Because of the condition’s multifactorial nature, patients achieve better outcomes when treated through coordinated, interprofessional care.[11][12][13][14]

Ulcer Classification Foot ulcers in individuals with diabetes primarily develop from neuropathy, ischemia, or a combination of both. They fall into 3 main categories: neuropathic, ischemic, and neuro-ischemic ulcers. Neuropathic ulcers Neuropathic ulcers result from peripheral neuropathy and commonly appear on the plantar surface, especially at pressure points, eg, the metatarsal heads and heel. These ulcers present as painless lesions with punched-out edges surrounded by callus (see Images. Diabetic Foot Ulcer and Neuropathic Ulceration). Their development reflects the combined effects of sensory and motor neuropathy, leading to abnormal pressure distribution across the foot. Neuropathy contributes to 60% to 70% of diabetic foot ulcers. Patients with sensory neuropathy fail to perceive minor trauma, allowing injuries to progress untreated in the setting of diminished pain sensation.[1][11] Ischemic ulcers Ischemic ulcers arise from PAD and usually occur on the tips of the toes or lateral borders of the feet. These ulcers tend to be painful, with irregular margins, pale skin, and cold extremities accompanied by absent peripheral pulses. PAD accounts for up to 50% of diabetic foot ulcers.[7][11][15] Neuro-ischemic ulcers Neuro-ischemic ulcers develop when both neuropathy and PAD coexist. They occur more frequently in older patients with long-standing diabetes and multiple comorbidities. The ulcer’s location depends on which factor predominates, and pain intensity varies between patients.[11][16][17] Diabetic Foot Ulceration Risk Factors Peripheral neuropathy represents a major risk factor for diabetic foot ulcers.[17] Motor neuropathy distorts normal foot anatomy, producing claw and hammer toe deformities, contracted medial arches (pes cavus), and prominent metatarsal heads, which lead to callus formation and plantar ulceration. Sensory neuropathy eliminates protective sensation, preventing awareness of pain, pressure, and temperature changes; repetitive micro-trauma then results in skin breakdown, significantly increasing the risk of ulcer development.[18][19] Autonomic neuropathy further contributes to reduced sweating, promoting dry, fissured skin, impaired microvascular regulation, and arteriovenous shunting, which increases vulnerability to ulceration and infection.[17]

Peripheral neuropathy represents a major risk factor for diabetic foot ulcers.[17] Motor neuropathy distorts normal foot anatomy, producing claw and hammer toe deformities, contracted medial arches (pes cavus), and prominent metatarsal heads, which lead to callus formation and plantar ulceration. Sensory neuropathy eliminates protective sensation, preventing awareness of pain, pressure, and temperature changes; repetitive micro-trauma then results in skin breakdown, significantly increasing the risk of ulcer development.[18][19] Autonomic neuropathy further contributes to reduced sweating, promoting dry, fissured skin, impaired microvascular regulation, and arteriovenous shunting, which increases vulnerability to ulceration and infection.[17] PAD doubles in prevalence among patients with diabetes compared to the general population and serves as a strong predictor of ulcer formation and poor healing. Diminished distal vascularization independently heightens the risk of ulcer formation, particularly when combined with neuropathy.[20] Decreased lower-extremity perfusion also correlates with increased risk of ulceration. Intersocietal guidelines recommend routine PAD screening and risk-based follow-up to improve early detection and management.[21] Chronic kidney disease (CKD) independently increases the likelihood of diabetic foot ulcers. Over one-third of individuals with diabetes develop CKD, and up to one-third of those individuals experience a foot ulcer during their lifetime. CKD elevates ulcer risk through higher rates of neuropathy, PAD, and immune dysfunction.[22] Dialysis further increases the prevalence to 21%, compared with 5% among those not on dialysis.[23] Patients with stage 4 and 5 CKD or those on dialysis face a 10- to 15-fold increase in major amputation risk.[24] Regular skin surveillance remains essential for individuals with end-stage renal disease.[25] Additional risk factors include prolonged duration of diagnosed diabetes, poor glycemic control, history of prior ulcer or amputation, older age, male sex, elevated body mass index, hypertension, and hyperlipidemia.[26][18] Each comorbidity compounds the risk of ulcer formation and impedes healing, underscoring the need for proactive, interprofessional prevention and management strategies.

Foot ulcers among individuals with diabetes represent a common and serious global health problem with significant clinical consequences. A 2017 systematic review of data from 16 countries reported a prevalence of 6.3%. Lifetime risk estimates for diabetic foot ulcers range from 19% to 34%.[1] Prevalence varies widely by region, with North America recording the highest rate (13%) and Oceania the lowest (3%). In Africa, the prevalence reached 7.2%, while 5.5% prevalnce was observed in Asia. Within the United States, Medicare fee-for-service data revealed a point prevalence of 8% among individuals with diabetes, with variation across regions and ethnic groups. The highest rates occurred among American Indian, Black, and Hispanic populations. Foot ulcers also occur more frequently in men (4.5%) than in women (3.5%). Patients with type 2 diabetes show a higher prevalence of 6.4%, compared with 5.5% in those with type 1 diabetes.[2] The risk of ulcer recurrence remains high, reaching 42% after 1 year and 65% after 5 years.[1] Mortality following a diabetic foot ulcer is considerable, with meta-analyses showing a 5-year mortality rate of approximately 50%. Patients undergoing major amputation face an even higher risk of death.[6][27] As global diabetes prevalence continues to rise, the total number of foot ulcer cases is expected to increase further, particularly in regions where access to interprofessional foot care teams remains limited.

Foot ulcers in individuals with diabetes develop through a complex interaction of neuropathy, abnormal foot biomechanics, PAD, impaired wound healing, and infection.[28] Hyperglycemic-driven metabolic and vascular injury results in loss of protective sensation, dry skin, muscle wasting, foot deformities, and elevated plantar pressures.[28] Increased plantar pressure combined with callus formation creates a mechanical environment highly susceptible to ulceration.[29] PAD occurs frequently among people with diabetes and accelerates tissue damage through increased vascular stiffness and reduced perfusion, ultimately contributing to ulcer formation and complications, eg, amputation.[7][30] Impaired wound healing further compounds these issues. Chronic low-grade inflammation, defective angiogenesis, fibroblast dysfunction, excessive matrix metalloproteinase activity, and accumulation of advanced glycation end products all hinder tissue repair, prolong ulcer persistence, and contribute to complications of diabetic foot ulcers.[31][32] Infection adds another layer of complexity. Polymicrobial biofilms commonly develop within diabetic foot ulcers, reducing immune system effectiveness and preventing adequate clearance of pathogens with antibiotic treatment. These biofilms perpetuate infection and inflammation, delaying healing and heightening the risk of severe complications.[33]

In histopathologic analysis, diabetic foot ulcers demonstrate a constellation of changes reflecting chronic ischemia, neuropathy, repetitive trauma, and impaired wound healing. The epidermis typically shows ulceration with loss of normal stratification at the wound edge, often accompanied by hyperkeratosis and acanthosis in adjacent skin due to chronic pressure. Re-epithelialization is frequently incomplete, and keratinocyte migration is disorganized.[34] The dermis is characterized by dense fibrocollagenous tissue with reduced and disarrayed granulation tissue formation. Fibroblasts are decreased in number and exhibit impaired proliferative activity. Capillary density is diminished, and small vessels often show basement membrane thickening, endothelial swelling, and hyaline change consistent with diabetic microangiopathy, contributing to local hypoxia.[35] Inflammatory infiltrates are typically chronic and mixed, composed predominantly of lymphocytes, plasma cells, and macrophages, with variable neutrophilic components in the setting of secondary infection. These inflammatory cells are often dysfunctional, resulting in a prolonged inflammatory phase. Areas of necrosis and fibrin deposition are common.[36] In longstanding ulcers, deeper tissues may demonstrate myonecrosis, fat necrosis, or osteomyelitis, with trabecular bone showing inflammatory destruction and reactive sclerosis. Overall, the histopathologic features of diabetic foot ulcers reflect a failure to transition from inflammation to effective tissue repair, underlying their chronicity and propensity for infection.

Clinical History A holistic assessment of every patient with diabetes presenting with a foot ulcer is the foundation of effective management. The evaluation begins with a detailed history that captures the ulcer’s location, duration, and precipitating cause (eg, trauma, barefoot ambulation). Clinicians should inquire about ulcer discharge, odor, and pain, as well as systemic symptoms, including fever, rigors, and malaise. Previous foot ulcers, antibiotic exposure, and any history of minor or major amputations or vascular surgery (eg, lower limb angioplasty or bypass procedures) must be documented. A thorough diabetes history should identify the type and duration of diabetes and any associated complications. Microvascular complications include retinopathy and neuropathy, while macrovascular conditions may involve cerebrovascular accidents, transient ischemic attacks, carotid artery disease, ischemic heart disease, and PAD. Glycemic control requires careful review, including frequency of hypoglycemic episodes, osmotic symptoms, and any episodes of diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar state. Medication use, particularly sodium-glucose cotransporter 2 (SGLT2) inhibitors, antiplatelet agents, statins, and anticoagulants, should be noted, along with adherence to therapeutic footwear or offloading devices. The history must also explore neuropathic symptoms, including hypoesthesia, hyperesthesia, paresthesia, dysesthesia, or anesthesia, and PAD-related symptoms (intermittent claudication, rest pain, and nonhealing ulcers). Smoking status and pack-year history, alcohol consumption, occupation, mobility, use of walking aids, and visual acuity require documentation. Medical comorbidities, eg, congestive heart failure or renal failure, can contribute to leg edema and must be addressed to optimize healing. The history concludes with an understanding of the patient’s ideas, concerns, and expectations to support patient-centered care. Clinical Examination

The history must also explore neuropathic symptoms, including hypoesthesia, hyperesthesia, paresthesia, dysesthesia, or anesthesia, and PAD-related symptoms (intermittent claudication, rest pain, and nonhealing ulcers). Smoking status and pack-year history, alcohol consumption, occupation, mobility, use of walking aids, and visual acuity require documentation. Medical comorbidities, eg, congestive heart failure or renal failure, can contribute to leg edema and must be addressed to optimize healing. The history concludes with an understanding of the patient’s ideas, concerns, and expectations to support patient-centered care. Clinical Examination A meticulous clinical examination follows. The lower limbs should be exposed from the knees to the toes and compared bilaterally. Inspection focuses on pallor, cyanosis, dependent rubor, mottling, edema, callus, corns, fissures, tinea pedis, and gangrene. Scars from revascularization or amputations, along with trophic changes, eg, hair loss, atrophic skin, muscle wasting, and nail deformities, should be noted. Interdigital maceration, heel cracks, and deformities, including claw toes, hammer toes, hallux valgus, pes cavus, and pes planus, require attention. Furthermore, signs of Charcot neuroarthropathy, including midfoot collapse, rocker-bottom deformity, bony prominence, erythema, and increased warmth, must be assessed. Additionally, the ulcer should be described in detail, noting its location, number, size, shape, edge, base, and surrounding callus (see Image. Diabetic Ulcer). The ulcer base may reveal granulation tissue, slough, necrosis, or exposed tendon, bone, or joint capsule. Edges may appear punched out, undermined, or macerated, while the surrounding skin may display erythema, warmth, induration, or edema. Exudate type and quantity—serous, purulent, or serosanguineous—should be recorded. The probe-to-bone test helps identify osteomyelitis when a gritty or bony resistance is felt. Sensory testing includes assessment of light touch, pinprick, vibration, joint position, and monofilament sensation.

Additionally, the ulcer should be described in detail, noting its location, number, size, shape, edge, base, and surrounding callus (see Image. Diabetic Ulcer). The ulcer base may reveal granulation tissue, slough, necrosis, or exposed tendon, bone, or joint capsule. Edges may appear punched out, undermined, or macerated, while the surrounding skin may display erythema, warmth, induration, or edema. Exudate type and quantity—serous, purulent, or serosanguineous—should be recorded. The probe-to-bone test helps identify osteomyelitis when a gritty or bony resistance is felt. Sensory testing includes assessment of light touch, pinprick, vibration, joint position, and monofilament sensation. Palpation should assess temperature, tenderness, and soft-tissue swelling, distinguishing between localized and diffuse edema. Peripheral pulses (dorsalis pedis, posterior tibial, popliteal, and femoral) must be palpated bilaterally, along with the abdomen, to detect an expansile pulsation suggestive of an abdominal aortic aneurysm. Charcot neuroarthropathy typically presents as a red, hot, swollen foot with bounding pulses and neuropathy, usually without ulceration. Chronic cases often present with foot deformity, strong pulses, and sensory loss. Examination also includes assessment of footwear and offloading techniques (eg, total contact casts, walkers, or insoles). Evaluation of the cardiovascular system helps identify heart failure contributing to extremity edema, while renal and liver assessment assist in detecting other causes of swelling. Diabetic Ulcer Classification Systems Several classification systems support standardized assessment of ulcer severity and infection. IWGDF/IDSA classification The International Working Group on the Diabetic Foot (IWGDF)/Infectious Diseases Society of America (IDSA) classification grades infection severity as follows: Grade 1: uninfected ulcers with no local or systemic signs Grade 2: mild infection with erythema ≤2 cm Grade 3: moderate infection with deeper involvement of muscle, joint, or bone, or erythema >2 cm without systemic toxicity Grade 4: severe infection with systemic inflammatory response [37] SINBAD score

The International Working Group on the Diabetic Foot (IWGDF)/Infectious Diseases Society of America (IDSA) classification grades infection severity as follows: Grade 1: uninfected ulcers with no local or systemic signs Grade 2: mild infection with erythema ≤2 cm Grade 3: moderate infection with deeper involvement of muscle, joint, or bone, or erythema >2 cm without systemic toxicity Grade 4: severe infection with systemic inflammatory response [37] SINBAD score The SINBAD score (site, ischemia, neuropathy, bacterial infection, and depth) provides a simple bedside tool for evaluating ulcer severity. Each domain receives a score of 0 or 1, yielding a total between 0 and 6. Higher scores correspond to worse healing rates and increased risk of amputation. Standardized documentation using SINBAD enhances audit and communication.[38] WIfI system The WIfI (Wound, Ischemia, foot Infection) system assigns scores from 0 to 3 across its domains and groups them into stages 1 to 4, estimating the 1-year risk of major amputation and the potential benefit of revascularization. A higher WIfI stage correlates with poorer healing outcomes and greater amputation risk, offering clinicians a structured approach to evaluating limb threat and guiding management decisions.[39]

Laboratory Studies Laboratory evaluation plays a crucial role in the assessment of diabetic foot ulcers, particularly for detecting infection and monitoring overall patient status. A complete blood count may reveal leukocytosis, specifically neutrophilia, though this finding may be absent even in severe infections due to diabetes-related immune alterations. C-reactive protein (CRP) is a nonspecific marker of infection or inflammation and may be elevated in various diabetic foot infections; however, normal CRP values should not be used to exclude infection. Erythrocyte sedimentation rate (ESR) often rises in inflammatory conditions; values of 70 mm/hour or higher suggest osteomyelitis. Elevated procalcitonin supports the presence of bacterial infection. These inflammatory markers function as adjuncts to clinical assessment and imaging rather than as sole diagnostic criteria.[33][40][41][42] Additionally, assessment of renal and liver function remains essential, as abnormalities may result from infection, sepsis, or antibiotic therapy. Measurement of HbA1c helps determine whether glycemic control needs to be optimized, as poor glycemic control impairs wound healing. Stress from infection may further destabilize glycemia, necessitating adjustment of oral hypoglycemic agents or escalation of insulin therapy.[43][44] Culture of suspected infected ulcers should prioritize tissue specimens obtained via curettage or biopsy for Gram staining and microbial identification. Superficial swab cultures are discouraged, and a bone biopsy should be considered if osteomyelitis is suspected and feasible.[33] Imaging Studies

Additionally, assessment of renal and liver function remains essential, as abnormalities may result from infection, sepsis, or antibiotic therapy. Measurement of HbA1c helps determine whether glycemic control needs to be optimized, as poor glycemic control impairs wound healing. Stress from infection may further destabilize glycemia, necessitating adjustment of oral hypoglycemic agents or escalation of insulin therapy.[43][44] Culture of suspected infected ulcers should prioritize tissue specimens obtained via curettage or biopsy for Gram staining and microbial identification. Superficial swab cultures are discouraged, and a bone biopsy should be considered if osteomyelitis is suspected and feasible.[33] Imaging Studies Imaging contributes significantly to diagnosis and management. Plain radiographs are indicated for ulcers extending beyond the skin, the presence of gas in soft tissue, visible bone exposure, or a positive probe-to-bone test (see Image. Right Foot Radiograph). Radiographs aid in identifying osteomyelitis, Charcot neuroarthropathy, and other pathologies (eg, fractures). However, early bone infection may not be detected, warranting magnetic resonance imaging (MRI) evaluation.[45] MRI provides a detailed assessment of osteomyelitis, deep soft-tissue infections, abscesses, septic arthritis, and Charcot neuroarthropathy when x-ray findings are inconclusive (see Image. Right Foot Osteomyelitis). Advanced imaging, including radionuclide scans or positron emission tomography (PET), may occasionally be required for confirmation.[33][45] Evaluation of Peripheral Artery Disease Evaluation of PAD utilizes multiple modalities (see Image. Peripheral Arterial Disease). Pedal Doppler waveform analysis, ankle-brachial index (ABI), and toe-brachial index (TBI) provide an initial noninvasive assessment. PAD is less likely with ABI values between 0.9 and 1.3, TBI 0.70 or greater, and triphasic or biphasic pedal waveforms. Low ankle pressures (<50 mm Hg) or ABI  less than 0.5 correlate with impaired healing and increased risk of major amputation.

Evaluation of PAD utilizes multiple modalities (see Image. Peripheral Arterial Disease). Pedal Doppler waveform analysis, ankle-brachial index (ABI), and toe-brachial index (TBI) provide an initial noninvasive assessment. PAD is less likely with ABI values between 0.9 and 1.3, TBI 0.70 or greater, and triphasic or biphasic pedal waveforms. Low ankle pressures (<50 mm Hg) or ABI  less than 0.5 correlate with impaired healing and increased risk of major amputation. Toe pressure measured with a pneumatic plethysmograph indicates healing probability; pressures 30 mm Hg or more improve healing odds by up to 30%, while values less than 30 mm Hg increase amputation likelihood by approximately 20%. Transcutaneous oxygen pressure (TcPO2) provides an alternative assessment when toe pressures cannot be obtained; TcPO2 values of 25 mm Hg or higher increase the probability of healing by 45%, and values below 25 mm Hg increase the risk of major amputation by 20%.[7] ABI may be falsely elevated in patients with diabetes due to vessel calcification, making toe pressures, TBI, and TcPO2 preferred measures. When revascularization is considered, imaging of the arterial system from the aorta to the pedal arch using computed tomography (CT) angiography, magnetic resonance angiography (MRA), or catheter-based digital subtraction angiography offers precise anatomical detail to guide intervention.[46][47]

Diabetic Foot Ulcer Management Management of foot ulcers and their complications requires a structured, evidence-based approach coordinated by an interprofessional diabetic foot team. Early referral is recommended following systematic evaluation, with urgent consultation warranted in cases of ischemia or moderate-to-severe infection.[33] Offloading remains the cornerstone of treatment for neuropathic plantar ulcers. For forefoot and midfoot ulcers, nonremovable knee-high devices, eg, total contact casts or nonremovable walkers, provide optimal pressure relief.[25][29] Regular sharp debridement of callus and necrotic tissue promotes healing, while dressings should be selected according to wound status, exudate level, patient-specific factors, and cost-effectiveness.[28] Antibiotic therapy is indicated only when clinical infection is present. Mild soft-tissue infections typically require 1 to 2 weeks of oral therapy, whereas moderate-to-severe infections often require 4 to 6 weeks of intravenous therapy, often initiated in a hospital setting. Treatment may be prolonged in cases with delayed resolution due to factors, eg, PAD.[33] Staphylococcus aureus predominates in mild infections, whereas severe or chronic infections are often polymicrobial, including gram-negative rods and anaerobes. Empiric therapy should cover gram-positive cocci in mild infections, with broader-spectrum antibiotics for moderate-to-severe infections or ischemic ulcers. Management of osteomyelitis complicating foot ulcers Osteomyelitis complicating foot ulcers may respond to medical management alone, particularly forefoot infections without PAD, exposed bone, or urgent drainage requirements, with antibiotics administered for approximately 6 weeks.[33][48] Minor amputations, eg, toe, ray, or transmetatarsal procedures, may be necessary for localized osteomyelitis, metatarsal involvement, necrotic tissue, septic arthritis, or exposed bone.[33] Following minor amputation with clean bone margins, antibiotics are recommended for 2 to 5 days, or up to 3 weeks if bone margin cultures are positive.

Osteomyelitis complicating foot ulcers may respond to medical management alone, particularly forefoot infections without PAD, exposed bone, or urgent drainage requirements, with antibiotics administered for approximately 6 weeks.[33][48] Minor amputations, eg, toe, ray, or transmetatarsal procedures, may be necessary for localized osteomyelitis, metatarsal involvement, necrotic tissue, septic arthritis, or exposed bone.[33] Following minor amputation with clean bone margins, antibiotics are recommended for 2 to 5 days, or up to 3 weeks if bone margin cultures are positive. Urgent surgical consultation is critical for moderate-to-severe infection with necrotizing fasciitis, deep abscesses, compartment syndrome, severe limb ischemia, or gangrene (see Image. Gangrenous Ulcers). Early debridement within 24 to 48 hours, combined with antibiotic therapy, improves outcomes. Ulcers showing less than 50% area reduction within 4 weeks should prompt reassessment for PAD.[33] Surgical interventions, eg, Achilles tendon lengthening, gastrocnemius recession, and metatarsal head resection, effectively prevent recurrence of plantar ulcers. Flexor tenotomy and hallux osteotomy address apical ulcers. Protective footwear and orthoses are essential to reduce the risk of recurrent ulceration.[29] Peripheral artery disease management Management of PAD requires urgent vascular evaluation for any infected ulcer with suspected ischemia or gangrene.[33] Revascularization, through endovascular angioplasty or bypass surgery, is indicated for significant arterial stenosis or critical limb ischemia, with decisions guided by vascular anatomy and patient comorbidities.[7][46] Major below-knee amputation may become necessary when infection and ischemia persist despite optimal medical, surgical, and vascular interventions.[33] Optimizing glycemic control, maintaining blood pressure within target ranges, and initiating statins and antiplatelet therapy are fundamental to improving outcomes and preventing recurrence.

Clinicians managing patients with diabetes must maintain a broad diagnostic perspective and consider alternative causes of foot and leg ulcers, guided by clinical presentation. Complications commonly linked to diabetes, eg, neuropathy and PAD, often coexist with other conditions and hinder healing, underscoring the need for comprehensive evaluation. Pressure Ulcers Pressure ulcers arise from prolonged immobility or poorly fitting footwear and typically develop over bony prominences, eg, the heel or lateral malleolus. Neuropathy and leg edema, particularly in older adults or bedbound individuals, heighten susceptibility to these ulcers. Preventive strategies rely on adequate offloading of pressure using simple assistive devices to avoid complications, eg, infection, sepsis, or osteomyelitis.[49] Vasculitis and Autoimmune Conditions Vasculitis and autoimmune disorders, including polyarteritis nodosa (PAN), anti-neutrophil cytoplasmic antibody (ANCA)–associated vasculitis, rheumatoid arthritis, scleroderma, and antiphospholipid syndrome, may contribute to ulcer formation. Such ulcers often appear in multiple sites across the lower legs and feet. Vasculitic processes account for up to 5% of cutaneous ulcers.[50][51] Pyoderma gangrenosum, a neutrophilic dermatosis associated with ulceration, begins as a pustule or bulla that progresses to a purulent ulcer with necrotic edges and surrounding erythema.[52] This condition frequently occurs in association with inflammatory bowel disease or ankylosing spondylitis. Venous Leg Ulcers Venous leg ulcers are the most common type of leg ulcer, affecting up to 3% of individuals older than 65 years. These ulcers usually occupy the gaiter region, most often above the medial malleolus, and result from chronic venous insufficiency and venous hypertension. They present as shallow wounds with irregular borders, sloping edges, and a yellow fibrinous base (see Images. Venous Leg Ulcer and Venous Stasis Ulcer). Accompanying features often include varicose veins, hyperpigmentation, and lipodermatosclerosis. When a person with diabetes presents with gaiter-area ulcers, evaluation for venous insufficiency and varicosities becomes essential.[53] Necrobiosis Lipoidica Diabeticorum

Venous leg ulcers are the most common type of leg ulcer, affecting up to 3% of individuals older than 65 years. These ulcers usually occupy the gaiter region, most often above the medial malleolus, and result from chronic venous insufficiency and venous hypertension. They present as shallow wounds with irregular borders, sloping edges, and a yellow fibrinous base (see Images. Venous Leg Ulcer and Venous Stasis Ulcer). Accompanying features often include varicose veins, hyperpigmentation, and lipodermatosclerosis. When a person with diabetes presents with gaiter-area ulcers, evaluation for venous insufficiency and varicosities becomes essential.[53] Necrobiosis Lipoidica Diabeticorum Necrobiosis lipoidica diabeticorum, often called shin spots, manifests as purplish-red papules or plaques on the shins that may become atrophic and yellow over time (see Image. Necrobiosis Lipoidica). This uncommon condition affects approximately 0.3% to 1.2% of individuals with diabetes. Lesions are generally asymptomatic and rarely require specific treatment.[54]

Healing of foot ulcers in individuals with diabetes depends on multiple clinical variables that shape both recovery and long-term outcomes. Poor prognostic indicators include the presence of PAD, extended ulcer duration, and multiple ulcers at initial presentation.[1][8] Nonmodifiable factors, eg, bony deformities—including prominent metatarsal heads or pes cavus—heighten the risk of recurrence and correlate with unfavorable results.[9] Ischemic ulcers generally predict poorer healing than neuropathic ulcers because of diminished perfusion and increased infection risk (see Image. Diabetic Neuropathic Ulcer).[7] Optimizing modifiable elements, eg, glycemic control, effective offloading, and management of comorbidities (eg, edema related to heart failure or renal disease), remains critical for promoting wound closure and recovery.[10] Risk of Amputation People with diabetes have a 10- to 20-fold higher likelihood of lower-limb amputation compared with the nondiabetic population.[15][55] Predictors of amputation include demographic and clinical features (eg, male gender, smoking, elevated body mass index, and advanced age).[15][56] Comorbidities, including PAD, neuropathy, chronic kidney disease, dependence on haemodialysis, and cardiovascular disease, further elevate risk.[15] Ulcer severity and infection play decisive roles; advanced lesions, gangrene, or severe infection greatly increase the likelihood of limb loss.[57] Cardiovascular Outcomes and Mortality The presence of diabetic foot ulcers often reflects widespread vascular pathology. Individuals with both diabetes and foot ulcers face markedly higher risks of ischemic heart disease, cerebrovascular accidents, and overall cardiovascular mortality compared with those without ulcers.[58] These patients experience significant mortality rates—approximately 15% within 12 months of ulcer onset and a 60% reduction in 5-year survival. Cardiovascular disease accounts for most deaths within this group.[8] Age, smoking, PAD, neuropathy, chronic kidney disease, and established cardiovascular disease all predict higher mortality.[4][8] Moreover, ulcer severity itself serves as an independent prognostic marker for mortality, highlighting the systemic nature of diabetic foot disease and its close link with vascular health.[4][57]

Foot ulcers in individuals with diabetes are associated with various complications, including: Infected ulcer and cellulitis (occur in over half of all foot ulcers) [59] Abscess Bacteremia/sepsis Osteomyelitis (common complication seen in up to 50% of foot ulcers) [60] Gangrene [16][61][8] Minor and major amputation (occurs in up to 30% of foot ulcer cases) [8][15][55][56] Poor glycemic control [43][44] Impaired quality of life Increased mortality [8][58]

Early detection and interprofessional management reduce short-term and long-term complications, including amputations and mortality.[12][13][14] The core members of the interprofessional team include the endocrinologist, vascular surgeon, orthopaedic surgeon, podiatrist, orthotist, and the limb rehabilitation team. Regular input is needed from the microbiologist, interventional radiologist, and sometimes from the plastic surgeon.

Preventing diabetic foot ulcers demands early identification of risk factors and consistent patient engagement. Education should focus on daily foot inspection, prompt reporting of blisters, calluses, or other skin changes, and proper foot hygiene. Patients must understand the importance of maintaining optimal glycemic control to reduce the risk of neuropathy and vascular complications. Regular podiatric or orthopedic evaluation, nail care by trained professionals, and the use of well-fitting, cushioned footwear significantly reduce the likelihood of ulcer development. Individuals with previous ulcers or deformities require ongoing follow-up and protective offloading devices to prevent recurrence. Teaching patients to avoid barefoot walking and exposure to extreme temperatures further limits trauma and skin breakdown. Effective patient education also extends to lifestyle modification and cardiovascular risk reduction. Encouraging smoking cessation, weight management, and regular physical activity enhances peripheral circulation and overall health.[25] Explicit instruction regarding medication adherence, including antiplatelet and lipid-lowering agents, strengthens preventive care. Interprofessional collaboration among physicians, nurses, podiatrists, orthotists, pharmacists, and diabetes educators enhances consistency in messaging and reinforces self-management behaviors. Empowering patients to recognize early warning signs and seek timely medical attention not only prevents complications, eg, infections and amputations, but also improves quality of life and long-term survival.[66]

Foot ulcers frequently develop in individuals with diabetes as a consequence of neuropathy and PAD. Complications range from localized infection to severe outcomes, eg, sepsis, bacteremia, osteomyelitis, septic arthritis, gangrene, and ultimately minor or major amputation. These ulcers significantly increase both morbidity and mortality, underscoring the need for vigilance and proactive care. Early detection and thorough assessment of foot ulcers and their complications remain vital to prevent progression. Prompt referral to an interprofessional diabetic foot team promotes optimal management, while hospital admission becomes necessary for patients presenting with moderate to severe infection, rapidly advancing tissue necrosis, systemic toxicity, or critical limb ischemia. Several pitfalls hinder effective management. Delayed recognition of infection or ischemia accelerates tissue destruction, and failure to assess for associated PAD and osteomyelitis compromises outcomes. Empirical antibiotic use without reference to the local antibiogram often leads to suboptimal treatment, and fragmented care lacking interprofessional coordination further worsens prognosis. Prevention relies on continuous patient education that emphasizes daily foot inspection, appropriate footwear, and early reporting of any lesions. Routine screening of high-risk individuals for neuropathy and PAD, coupled with optimization of glycemic control and lipid management, enhances protective measures. Timely correction of modifiable risk factors, eg, callus formation and structural deformities, through podiatric and orthotic intervention strengthens long-term prevention and promotes durable limb preservation.

Diabetic foot ulcers are one of the most serious complications of diabetes, arising from neuropathy, peripheral arterial disease, and impaired wound healing. These ulcers predispose patients to infections, osteomyelitis, gangrene, and amputation, contributing to high morbidity and mortality. Early detection, prompt referral, and comprehensive interprofessional management are vital to improving outcomes and preventing recurrence. Effective management demands collaboration among healthcare professionals who integrate clinical expertise, communication, and shared decision-making. Physicians and advanced practitioners assess vascular and neurological status, optimize glycaemic control, and coordinate surgical or vascular interventions. Nurses provide wound care, patient education, and infection monitoring, while pharmacists ensure safe and effective use of antibiotics and cardiovascular medications. Podiatrists and orthotists play key roles in offloading pressure and preventing deformity-related recurrence. Continuous communication across the team fosters seamless transitions between inpatient and outpatient care, enhances safety, and strengthens adherence to individualized treatment plans that promote healing and limb preservation.