What is the most significant risk factor for a medial foot ulcer in a 36‑year‑old man with diabetes mellitus?

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

In a 36-year-old man with diabetes presenting with a medial foot ulcer, diabetes mellitus (option A) represents the highest risk because it is the underlying systemic disease that drives all three pathophysiological mechanisms—peripheral neuropathy, peripheral arterial disease, and foot deformities—that converge to cause ulceration. 1, 2

Why Diabetes is the Primary Risk Factor

The International Working Group on the Diabetic Foot (IWGDF) identifies diabetes as the foundation upon which foot ulcers develop, with a lifetime incidence of 19-34% among all diabetic patients 2. The pathophysiology operates through three interconnected mechanisms that stem directly from diabetes 1, 2:

• Peripheral neuropathy (loss of protective sensation) is present in 78% of diabetic foot ulcers and represents the single most common component cause 1
• Peripheral arterial disease affects up to 50% of patients with diabetic foot ulcers 2
• Foot deformities develop from motor neuropathy and create high-pressure points that lead to ulceration 1, 2

Why Not Atherosclerosis or Venous Hypertension Alone

While atherosclerosis (option B) contributes to peripheral arterial disease in diabetic patients, it is a component mechanism rather than the primary risk factor 1. Atherosclerosis in isolation—without the neuropathic component from diabetes—rarely causes medial foot ulcers because patients retain protective sensation and avoid repetitive trauma 2.

Venous hypertension (option C) is not a recognized risk factor for diabetic foot ulcers in any major guideline 1. Venous ulcers typically occur on the lateral malleolus or gaiter area of the leg, not the medial foot, and present with different clinical features (edema, hemosiderin staining, lipodermatosclerosis) 1.

Clinical Assessment Framework

For this 36-year-old diabetic patient, immediately assess the following 1, 2:

• Neurological status: Perform 10-g monofilament testing plus one additional test (pinprick, vibration with 128-Hz tuning fork, or ankle reflexes) to confirm loss of protective sensation 1
• Vascular status: Palpate dorsalis pedis and posterior tibial pulses; if diminished, obtain ankle-brachial index (ABI) and toe pressures 1
• Foot deformities: Examine for bunions, hammertoes, prominent metatarsal heads, or Charcot changes 1
• Ulcer history: Document any prior ulceration or amputation, which places him in IWGDF risk category 3 (highest risk) 1, 2

Risk Stratification and Prognosis

This patient automatically falls into IWGDF risk category 3 (high risk) because he has an active ulcer 2. After healing, he faces 2:

• 40% recurrence rate within 1 year 2
• 65% recurrence rate within 3 years 2

Common Pitfalls to Avoid

• Do not attribute the ulcer solely to atherosclerosis or PAD without recognizing diabetes as the underlying systemic condition that enables ulcer formation through the neuro-ischemic triad 2
• Do not overlook neuropathy assessment—even if pulses are palpable, neuropathy alone can cause ulceration through repetitive unrecognized trauma 1
• Do not delay vascular evaluation if toe pressure <30 mmHg or transcutaneous oxygen pressure <25 mmHg, as these thresholds indicate inability to heal and need for urgent revascularization 2