The primary pathophysiology involves incompetent one-way venous valves or dysfunctional calf muscle pumping leading to insufficient venous blood return to the heart and chronic leg venous hypertension. This venous hypertension leads to aberrant tissue perfusion and subsequent decreased delivery of oxygen and nutrients, failure to remove metabolic byproducts, and tissue ischemia.
Additional commonly associated clinical features include leg and ankle edema, varicose veins, yellow-brown pigmentation secondary to hemosiderin deposition and extravasated red blood cells, eczematous changes with scaling and crusting (stasis dermatitis), and lymphedema. Lipodermatosclerosis is also seen and corresponds to fibrotic changes in subcutaneous tissue leading to a hard and indurated feel to the skin. An "inverted champagne bottle" leg indicates end stage lipodermatosclerosis and is caused by severe fibrotic changes in the distal leg and leg edema of the proximal leg. Atrophie blanche are smooth, ivory-colored atrophic plaques secondary to sclerosis seen in approximately 40% of patients with venous insufficiency.
Additional key points that the clinician should note are that stasis ulcers usually begin on the medial malleolus but may become circumferential over time. They may be painful, are difficult to treat, and frequently recur. They may become secondarily infected.
I83.009 – Varicose veins of unspecified lower extremity with ulcer of unspecified site
371032004 – Stasis ulcer
- Arterial ulcers – Weak or absent distal pulses, does not have surrounding areas of dermatitis, has a punched-out appearance; located anteriorly or laterally on the lower extremity consistent with pressure sites.
- Neurogenic (diabetic) ulcer – Almost invariably has peripheral neuropathy with decreased sensation and HgbA1C that is elevated; look for punched-out ulcers that are in pressure sites.
- Pyoderma gangrenosum – Look for very painful ulcers that have an irregular necrotic, undermined, overhanging border; these can occur anywhere.
- Thromboangiitis obliterans – Weak or absent distal pulses. Patients almost invariably have a history of smoking. Upper limb involvement is also seen.
- Cryofibrinogenemia – Look for associated livedo reticularis and purpura.
- Acroangiodermatitis – Although they do not often ulcerate, lesions are commonly seen in conjunction with venous hypertension and manifest as violaceous patches and plaques that appear on the extensor surfaces of the distal lower extremities.
- Sickle cell ulcer
- Bullous impetigo
- Squamous cell carcinoma
- Atypical mycobacterium infection
- Panniculitis with ulceration