Venous Ulcers

Cutaneous ulceration resulting from venous insufficiency.

Venous ulcers are a major cause of morbidity in elderly patients. Causes include incompetent superficial veins and perforators and postphlebitic syndrome. These factors result in persistent venous hypertension and a corresponding rise in capillary pressure with fibrinogen leakage into the tissues. Pericapillary fibrin cuffs form, limiting the diffusion of oxygen and other nutrients to the skin, predisposing it to ulceration.

Symptoms and Signs

Venous ulcers commonly occur on the medial or lateral aspect of the legs. Edema, hyperpigmentation due to hemosiderin deposition, eczematous changes, and induration often occur on surrounding skin. Distinctive scars composed of sharply demarcated, sclerotic, atrophic, white plaques (termed atrophie blanche) stippled with telangiectasia and surrounded by hyperpigmentation commonly occur in patients with venous insufficiency. Woody induration of the involved areas indicates lipodermatosclerosis, a scarlike process thought to result from tissue hypoxia and increased cellular matrix turnover that often gives the lower leg an inverted champagne bottle appearance.

Basal cell or squamous cell carcinomas sometimes arise in long-standing ulcers.

Diagnosis

Diagnosis is made clinically. All patients with venous ulcers should be evaluated for systemic disorders such as heart failure, hypoalbuminemia, neuropathy, diabetes mellitus, arterial insufficiency, and nutritional deficiencies, which may contribute to the condition. Such evaluation is critical even if there is a clear venous component, because leg ulcers often have multiple etiologies.

Areas suggestive of malignancy require biopsy; if results are positive, referral to a surgeon for definitive treatment is necessary.

Treatment

Reducing edema is the major treatment goal. The patient should be advised to elevate the affected limb whenever possible. Compression stockings and graduated pressure bandages or Unna's boot, applied from toe to knee, effectively reduce limb edema. Diuretics, although widely prescribed, usually do not play a significant role in treatment and may be dangerous in the elderly. Techniques for ulcer dressing and possible debridement are the same as those described for pressure sores.

Systemic antibiotics do not enhance healing unless cellulitis is present.

If signs of cellulitis (erythema, swelling, warmth, lymphangitic streaking) develop around the ulcer, a wound culture should be taken (however, determining whether a positive culture represents colonization or active infection can require considerable clinical acumen). The patient should immediately be given dicloxacillin 250 to 500 mg qid or a 1st-generation cephalosporin for 7 to 10 days. Oral administration is usually appropriate, although rapidly progressive or facial lesions may warrant IV antibiotics initially. If the patient is allergic to penicillin, erythromycin or clindamycin can be substituted. If the wound is infected with Pseudomonas sp. (which often produces a fruity smell), frequent applications of compresses with acetic acid 5% reduce the bacterial count. Antibiotic sensitivity of all cultured organisms should be noted, because drug resistance is common.

Patients with venous ulcers and stasis dermatitis are at risk of developing allergic contact dermatitis from topical antibiotics or other potential sensitizers applied to the broken skin surface. Chronic, low-grade delayed hypersensitivity reactions (allergic contact dermatitis) may impede ulcer healing and increase local pruritus and edema. Wood alcohols, balsam of Peru, antibiotic ointments (neomycin and bacitracin), wool alcohols (lanolin), and fragrances are among the most commonly implicated allergens. However, all contactants are potential culprits, from the prescribed dressings to OTC products and even articles of clothing. When an allergy is suspected, topical therapy should be discontinued for at least 2 weeks, and the ulcer should be treated with saline wet-to-dry compresses. If possible, patch testing should be performed.

Patients with very deep or nonhealing ulcers may require surgical intervention. Split-thickness skin grafts, pinch grafts, or commercially available cultured allografts may speed healing.

Bed rest and elevation are generally helpful in ulcer therapy, but the benefits of immobilization must be weighed against the risk of deep vein thrombosis and deconditioning.