In a 36-year-old man with diabetes mellitus and a medial foot ulcer, which is the greatest risk factor: diabetes mellitus, atherosclerosis, or venous hypertension?

Diabetes Mellitus is the Highest Risk Factor for This Medial Foot Ulcer

In this 36-year-old diabetic male with a medial foot ulcer, diabetes mellitus (DM) is the greatest risk factor, as it is the underlying systemic disease that drives all the pathophysiological mechanisms leading to foot ulceration, including neuropathy, peripheral arterial disease, and impaired wound healing. 1

Why Diabetes is the Primary Risk Factor

Diabetes as the Root Cause

• Diabetes mellitus is the fundamental disease process that creates the conditions for foot ulceration through multiple interconnected pathways, with a lifetime incidence of 19-34% and yearly incidence of 2% in diabetic patients 1
• The International Working Group on the Diabetic Foot (IWGDF) identifies three key pathological mechanisms all stemming from diabetes: loss of protective sensation (LOPS), peripheral artery disease (PAD), and foot deformity 1, 2
• 78% of diabetic foot ulcers have peripheral neuropathy as a causal component, and more than 63% present with the triad of peripheral sensory neuropathy, minor trauma, and foot deformity 3

Why Not Atherosclerosis Alone?

• While atherosclerosis (PAD) is present in up to 50% of diabetic foot ulcers, it is typically a consequence of the underlying diabetes rather than an independent primary risk factor in this context 2, 4
• PAD in diabetics typically affects distal vessels and requires the presence of diabetes-related neuropathy to result in ulceration 4, 5
• The medial foot location is atypical for pure ischemic ulcers, which more commonly occur on toe tips, heels, or lateral foot borders over bony prominences 6

Why Not Venous Hypertension?

• Venous hypertension causes ulcers on the medial leg (gaiter area), not the medial foot 6
• The clinical presentation described—a 36-year-old diabetic with a medial foot ulcer—does not fit the typical venous ulcer profile, which would be expected in older patients with chronic venous insufficiency and would present more proximally on the medial malleolus or lower leg
• Diabetic foot ulcers occur on plantar surfaces, areas of high pressure from deformities, or over bony prominences on the foot itself 6, 3

Clinical Reasoning for This Case

Age and Location Considerations

• At 36 years old, this patient is relatively young for significant atherosclerotic disease to be the primary driver, though diabetes accelerates vascular disease 7
• The medial foot location essentially rules out typical neuropathic plantar ulceration (which requires repetitive mechanical stress on an insensate plantar surface) but is consistent with diabetic foot complications related to pressure points or minor trauma in the setting of neuropathy 6, 3

The Diabetic Cascade

• Diabetes creates the perfect storm: sensory neuropathy leads to loss of protective sensation, motor neuropathy contributes to foot deformities, and autonomic neuropathy reduces sweating leading to dry skin prone to cracking 2
• Even if PAD is present, it is the combination of diabetes-induced neuropathy plus vascular insufficiency that creates the neuro-ischemic ulcer, not atherosclerosis acting independently 8, 5, 7

Risk Stratification Context

• This patient would be classified as IWGDF risk category 1-3 depending on whether he has LOPS, PAD, foot deformity, or previous ulceration history 1, 2
• The presence of an active ulcer automatically places him at high risk for recurrence (40% within one year, 65% within three years after healing) 1, 2

Essential Evaluation

• Assess for loss of protective sensation using 10g monofilament testing 3
• Evaluate vascular status by palpating pedal pulses and measuring ankle-brachial index (ABI), with <0.9 indicating PAD 1, 6
• Consider toe pressures or transcutaneous oxygen pressure (TcPO₂) if ABI is falsely elevated due to arterial calcification (common in diabetes) 1, 6
• Urgent vascular imaging and revascularization should be considered if toe pressure is <30 mmHg or TcPO₂ <25 mmHg 1

Common Pitfall to Avoid

• Do not attribute this ulcer solely to atherosclerosis or venous disease without recognizing that diabetes is the underlying systemic condition that enables ulcer formation through multiple mechanisms 1, 2, 9
• The medial foot location should prompt evaluation for pressure points, minor trauma in the setting of neuropathy, or neuro-ischemic disease—all complications of diabetes 6, 3, 5