Leg ulcers
Leg ulcers affect 1% of the adult population and account for 1% of dermatology referrals. They are twice as common in women as in men and are a major burden on the health service. One half is venous, a tenth arterial and a quarter ‘mixed’ – due to venous and arterial disease. The remainder are due to rare causes.
Venous disease
Aetiopathogenesis
The superficial low-pressure venous system of the leg is connected to the deep higher pressure veins by perforating veins. Blood flow relies on the pumping action of surrounding muscles and the integrity of valves. Valve incompetence, occasionally congenital but usually due to damage by thrombosis or infection, results in a rise in capillary hydrostatic pressure and permeability (Fig. 1). Fibrin is deposited as a pericapillary cuff, interfering with diffusion of nutrients and resulting in disease.
Clinical presentation
Heaviness and oedema: early symptoms. The legs feel heavy and swell.
Discoloration: brown haemosiderin deposits from extravasated red cells. Telangiectasia and white lacy scars (atrophie blanche) occur at the ankle (Fig. 2).
Eczema: commonly occurs (p. 38), often complicated by allergic or irritant contact dermatitis.
Ulceration: often follows minor trauma, and typically affects the medial and, to a lesser extent, the lateral malleolus (Fig. 3). Neglected ulcers enlarge and may encircle the lower leg. Initially, venous ulcers are exudative but, under favourable conditions, they granulate and enter a healing phase in which the epidermis grows in from the sides and from small epithelial islands in the middle. Healing is invariably slow, often taking months. Some large ulcers never heal.
Post-ulcer leg: fibrosis may lead to a slender sclerosed ankle.
Differential diagnosis and complications
Venous ulcers can be differentiated from other ulcers (Table 1) by history, position and additional signs. Arterial ulcers are deep, painful and gangrenous, and situated on the foot or mid-shin. Complications of venous ulcers are common and include the following:
