Venous Hypertension (B) is the Most Likely Cause
In a diabetic patient with an unhealed ulcer on the medial aspect of the leg, venous hypertension is the most likely cause, as medial malleolar location is the classic presentation of venous ulcers, whereas diabetic and atherosclerotic ulcers typically occur on the plantar foot or over bony prominences distally. 1
Location is the Key Diagnostic Feature
- Venous ulcers characteristically occur over the medial malleolus and are generally irregular and shallow with well-defined borders 1
- Diabetic foot ulcers due to neuropathy occur on plantar surfaces of the forefoot, midfoot, or areas of high pressure from deformities 2
- Atherosclerotic (ischemic) ulcers in diabetics typically present on the toes, heel, or lateral foot over bony prominences, not the medial leg 2
Understanding the Pathophysiology
Venous Ulcers
- Venous hypertension from venous reflux or obstruction is the primary mechanism for venous ulcer formation 1
- These are the most common type of chronic lower extremity ulcers, affecting 1-3% of the U.S. population 1
- Associated findings include varicose veins, edema, venous dermatitis, lipodermatosclerosis, and atrophie blanche 1
Diabetic Foot Ulcers
- Diabetic peripheral neuropathy, not vascular disease, plays the central role in diabetic foot ulcer development 3
- Loss of protective sensation allows minor trauma to go unnoticed on weight-bearing surfaces 3
- Motor neuropathy creates foot deformities (claw toes, hammer toes) causing high-pressure areas on the plantar foot 3
Critical Clinical Distinction
The medial leg location essentially rules out typical diabetic neuropathic ulceration, which requires repetitive mechanical stress on an insensate plantar surface 2, 3. While diabetic patients can have peripheral arterial disease affecting up to 50% of cases 3, atherosclerotic ulcers present distally on toes and feet, not the medial leg 2.
Important Caveat: Mixed Etiology
- In patients with chronic non-healing leg ulcers, multiple etiologies commonly coexist 4, 5
- One study found that 92% of patients with chronic leg ulcers had both arterial and venous disease, with only 17% having isolated venous disease 5
- The combination of diabetes with venous insufficiency is increasingly common 4
Diagnostic Approach
- Examine for signs of venous disease: varicose veins, edema, hemosiderin staining, lipodermatosclerosis 1
- Palpate pedal pulses and measure ankle-brachial index to assess for coexisting arterial disease 2
- An ABI <0.9 indicates peripheral arterial disease, though it may be falsely elevated in diabetics due to arterial calcification 2
- Consider toe pressures or transcutaneous oxygen pressure (TcPO2) for more accurate vascular assessment in diabetics 2