Chronic leg ulcer is an open lesion between the knee and ankle joint that remains unhealed for at least 4 weeks

Aetiology

• 60-80% venous - due to venous blood stasis
• 22% arterial - manifestation of peripheral vascular disease
• 5% diabetic - diabetes impedes the normal stages of wound healing
• Other rare causes include autoimmune vasculitis (e.g. associated with rheumatoid arthritis, SLE), tropical disease and TB
• Often multifactorial
• Prevalence increases with age

Pathophysiology

Arterial ulcers

• Caused by insufficient blood supply due to peripheral vascular disease

Venous ulcers

1. Elevation of venous pressure in the legs e.g. by abdominal obesity which resists venous return from the legs
2. Veins dilate and valves become incompetent, varicose veins develop
3. The increased hydrostatic pressure in the vessels results in red blood cell leakage into the tissue resulting in swelling, haemosiderin, pigmentation and inflammation (due to breakdown products) i.e. venous (stasis) dermatitis
4. The skin cannot heal well due to poor blood supply, so begins to break down
5. Venous insufficiency also acts as a risk factor for DVT/PE

Clinical features

Clinical features of venous ulcers

• Most venous ulcers (87%) occur in the gaiter area