Leg ulcers occur relatively commonly in late middle and old age, arising in association with chronic venous insufficiency, chronic arterial insufficiency, or peripheral sensory neuropathy; in some patients, a combination of these factors. Leg ulcers are associated with significant long-term morbidity and often do not heal unless the underlying problem(s) is corrected.
Causes of Leg Ulcers
Venous Ulcers In half of patients venous ulcers are associated with prior venous thrombosis and in the other half with incompetence of superficial or communicating veins. Calf muscle pump dysfunction may occur because of deep venous insufficiency or obstruction, perforator incompetence, superficial venous insufficiency, arterial fistulas, neuromuscular dysfunction; commonly, a combination of these factors is in play. High venous pressure associated with capillary tortuousity and increased capillary permeability to large molecules results in deposition of a pericapillary fibrin layer. This layer is a barrier to diffusion of oxygen and other nutrients, resulting in ischemia and necrosis. Factors precipitating epidermal necrosis include minor trauma (scratch, knock) or contact dermatitis.
Arterial Ulcers – Arterial leg ulcers are caused by poor blood circulation as a result of narrowed arteries. They are also caused by damage to the small blood vessels from long-standing diabetes.
Diabetes also increases the likelihood of atherosclerosis (narrowing of the arteries). This means people with diabetes have a much increased risk of developing arterial ulcers.
Neuropathic Ulcers Foot ulcers in diabetic patients are usually associated with both sensory neuropathy and ischemia, often complicated by infection. Pressure over prominences of foot leads progressively to callosity formation, autolysis, and finally ulceration.
Symptoms of Leg Ulcers
The features of venous and arterial ulcers differ somewhat.
Symptoms of Venous ulcers
- Relatively painless unless infected.
- Associated with aching, swollen lower legs that feel more comfortable when elevated.
- Located below the knee, most often on the inner part of the ankles.
- Surrounded by mottled brown or black staining and/or dry, itchy and reddened skin
Symptoms of Arterial ulcers:
- Usually found on the feet, heels or toes.
- Cramp-like pains in the legs when walking, known as intermittent claudication, as the leg muscles do not receive enough oxygenated blood to function properly.
- The borders of the ulcer appear as though they have been ‘punched out’.
- Cold white or bluish, shiny feet.
- Frequently painful, particularly at night in bed or when the legs are at rest and elevated.
Diabetic ulcers have similar characteristics to arterial ulcers but are more notably located over pressure points such as heels, tips of toes, between toes or anywhere the bones may protrude and rub against bedsheets, socks or shoes. In response to pressure, the skin increases in thickness (callus) but with a minor injury breaks down and ulcerates.
Diagnosis
History and clinical findings confirmed by appropriate laboratory examinations.
Treatment
In general, factors such as anemia and malnutrition should be corrected to facilitate healing. Control hypertension. Weight reduction in the obese. Exercise; mobilize patient. Correct edema caused by cardiac, renal, or hepatic dysfunction. Secondary infection should be treated with effective antibiotics.
Venous Ulcers Ulceration tends to be recurrent unless underlying risk factors are corrected, i.e., corrective surgery and/or elastic stockings worn on a daily basis; beware of excess compression in patients with underlying arterial occlusion. Leg elevation. Unna boot; replace weekly. Intermittent pneumatic compression.
Treat Underlying Eczematous Dermatitis Whether atopic, stasis, or allergic contact eczematous dermatitis, should be treated initially with moist dressings for the acute exudative phase and subsequently with moderate to potent glucocorticoid ointment for a limited time. Hydrated petrolatum for xerosis.
Debridement Moist saline dressings, changed frequently. Surgical debridement to remove necrotic tissue.
Systemic Antimicrobial Agents Treat secondarily infected ulcer or complications of lymphangitis or cellulitis.
Skin Grafting Large ulcers with healthy granulation tissue in the base can be grafted by pinch or split-thickness methods. The patient’s own epidermis can be cultured in vitro and used for grafting.
Arterial Ulcers Symptomatic Analgesics for ischemic pain.
Increase Local Blood Flow Stop smoking. Control hypertension, diabetes. Exercise to increase collateral circulation. Elevate head of bed. Keep legs and feet warm.
Debridement Moist saline dressings, changed frequently. Surgery is usually contraindicated.
Systemic Antimicrobial Agents Treat secondarily infected ulcer or complications of lymphangitis or cellulitis.
Arterial Reconstruction Endarterectomy to remove localized atheromatous plaques; reconstruction/bypass of occluded areas. Consider in patients with pain at rest or failure of ulcer to heal.
Treatment Debride callus around ulcer margin. Total-contact plaster casting removes pressure from ulcer site.
Prevention
- Distribute weight off pressure points with special shoes.
- Stop smoking.
- Lose weight if you are overweight.
- If you have to stand for more than a few minutes, try to vary your stance as much as possible.
- When sitting, wriggle your toes, move your feet up and down and take frequent walks.
- Avoid sitting with your legs crossed.
References