Leg Ulcers: Types, Causes and Treatment

Types of leg ulcers

Many older people have mixed venous and arterial disease.

Causes and risk factors

Venous ulcers

Venous ulcers are caused by chronic venous insufficiency. Valves in the leg veins fail, so blood pools and pressure in the veins stays high when you stand. Fluid and proteins leak into the skin, which becomes inflamed, stained and fragile. A minor knock can then open into an ulcer that will not heal. Risk factors:

• varicose veins
• a previous deep vein thrombosis
• obesity
• long periods of standing or sitting
• reduced ankle movement or calf muscle weakness
• older age and multiple pregnancies

Arterial ulcers

Arterial ulcers result from peripheral artery disease, in which narrowed arteries reduce blood flow to the leg. Skin starved of oxygen breaks down easily and cannot heal. Smoking, diabetes, high blood pressure, high cholesterol and older age are the main risk factors.

Diabetic foot ulcers

Diabetes damages the nerves in the feet, so injuries are not felt, and often reduces blood flow too. Diabetic foot ulcers usually form under pressure points and can become deeply infected without much pain.

Less common causes

• pressure ulcers in people who are immobile
• vasculitis (inflamed blood vessels) and rheumatoid arthritis
• pyoderma gangrenosum: rapidly growing, very painful ulcers with purple edges, often with inflammatory bowel disease
• sickle cell disease
• skin cancers, such as squamous cell carcinoma, which can form in or mimic a long-standing ulcer
• infections, injuries and insect bites in people with poor circulation

Symptoms

• an open sore that does not heal
• swelling of the ankle or leg
• itching, aching or a heavy feeling in the leg
• weeping fluid, sometimes a lot
• discolored, hard or eczema-like skin around the ankle
• pain that varies with the type of ulcer

Signs of infection

• increasing pain
• redness or warmth spreading into the surrounding skin
• more swelling
• pus, a bad smell or green discharge
• fever or feeling unwell

Infection can spread to the skin (cellulitis) or bone and needs antibiotics.

How leg ulcers are diagnosed

A doctor or specialist nurse will examine the ulcer and both legs, and ask about varicose veins, clots, diabetes, smoking and how long the wound has been present. Key tests:

• Ankle-brachial index (ABI): compares blood pressure at the ankle and arm. It must be checked before compression, because compression can damage a leg with poor arterial supply.
• Venous duplex ultrasound: shows faulty veins and whether vein treatment would help.
• Blood tests: blood sugar, blood count, kidney function and markers of inflammation.
• Swabs: only when infection is suspected.
• Biopsy: for ulcers that look unusual or fail to heal despite good treatment.

Treatment

Venous ulcers

• Compression therapy: multilayer bandages or compression stockings squeeze the leg, reducing vein pressure and swelling. This is the most important treatment and heals most venous ulcers within months.
• Leg elevation: raise your legs above the level of your heart for 30 minutes several times a day.
• Walking and ankle exercises: activate the calf muscle pump.
• Vein treatment: closing faulty superficial veins (endovenous ablation) speeds healing and reduces recurrence.

Arterial ulcers

• Restoring blood flow with angioplasty, stents or bypass surgery.
• No strong compression.
• Stopping smoking, and medicines for cholesterol, blood pressure and clot prevention.

Diabetic foot ulcers

• Offloading: special boots, casts or shoes that take pressure off the wound.
• Removing dead tissue and callus (debridement).
• Tight blood sugar control and treatment of infection.
• Regular review by a foot care team.

Wound care for all types

• Cleaning with water or saline at each dressing change.
• Dressings chosen to manage moisture: absorbent ones for heavy weeping, others for dry wounds.
• Moisturizing the surrounding skin and treating eczema.
• Antibiotics only for confirmed infection.
• Good nutrition, with enough protein, to support healing.

Preventing leg ulcers from coming back

Venous ulcers come back in many people. To reduce the risk:

• wear compression stockings every day, lifelong if advised
• keep moving, and avoid standing or sitting still for long
• raise your legs when resting
• moisturize the skin daily and protect it from knocks
• manage weight, and do not smoke
• if you have diabetes, check your feet daily and wear well-fitting shoes

Frequently asked questions

What causes leg ulcers?

Most are caused by poor vein function (venous insufficiency), which raises pressure in the leg and damages the skin. Others come from poor arterial blood flow, diabetes damaging nerves and circulation, pressure, and less commonly inflammatory conditions or skin cancer.

How long does a leg ulcer take to heal?

With compression and good wound care, most venous ulcers heal within 3 to 4 months, though some take longer. Arterial and diabetic ulcers depend on improving blood flow or offloading pressure. An ulcer that is not shrinking after 4 to 6 weeks needs specialist review.

Why is my leg ulcer not healing?

Common reasons are lack of compression for a venous ulcer, poor arterial circulation, infection, uncontrolled diabetes, smoking, poor nutrition and swelling. Rarely, a non-healing ulcer is skin cancer or an inflammatory condition. A specialist can check circulation and take a biopsy if needed.

How can I tell if a leg ulcer is infected?

Signs of infection are increasing pain, spreading redness or warmth, more swelling, pus or a bad smell, and fever or feeling unwell. See a doctor promptly. Infected ulcers need antibiotics and can spread to the skin or bone.

Can I use compression stockings for any leg ulcer?

No. Compression is the main treatment for venous ulcers, but it can reduce blood flow further in a leg with peripheral artery disease and cause serious harm. A doctor or nurse should check your ankle-brachial index before you start compression.