Leg ulcers are wounds or breaks in the skin that do not heal or heal slowly due to underlying pathology. They have the potential to get progressively larger and become more difficult to heal over time. There are four common types of skin ulcers:
- Venous ulcers
- Arterial ulcers
- Diabetic foot ulcers
- Pressure ulcers
This section mainly covers arterial and venous ulcers.
Arterial ulcers result from insufficient blood supply to the skin due to peripheral arterial disease.
Venous ulcers occur due to the pooling of blood and waste products in the skin secondary to venous insufficiency.
Mixed ulcers are a combination of arterial and venous disease causing the ulcer.
Other Types of Ulcers
Diabetic foot ulcers are more common in patients with diabetic neuropathy. Patients who have lost the sensation in their feet are less likely to realise they have injured their feet or have poorly fitting shoes. Additionally, damage to both the small and large blood vessels impairs the blood supply and wound healing. Raised blood sugar, immune system changes and autonomic neuropathy also contribute to ulceration and poor healing. Osteomyelitis (infection in the bone) is an important complication.
Pressure ulcers typically occur in patients with reduced mobility, where prolonged pressure on particular areas (e.g., the sacrum whilst sitting) lead to the skin breaking down. This happens due to a combination of reduced blood supply and localised ischaemia, reduced lymph drainage and an abnormal change in shape (deformation) of the tissues under pressure. Extensive effort should be taken to prevent pressure ulcers, including individual risk assessments, regular repositioning, special inflating mattresses, regular skin checks and protective dressings and creams. The Waterlow Score is a commonly used risk assessment tool for estimating an individual patient’s risk of developing a pressure ulcer.
Arterial Versus Venous Ulcers
Some features help you distinguish between arterial and venous ulcers.
Typically, arterial ulcers:
- Occur distally, affecting the toes or dorsum of the foot
- Are associated with peripheral arterial disease, with absent pulses, pallor and intermittent claudication
- Are smaller than venous ulcers
- Are deeper than venous ulcers
- Have well defined borders
- Have a “punched-out” appearance
- Are pale colour due to poor blood supply
- Are less likely to bleed
- Are painful
- Have pain worse at night (when lying horizontally)
- Have pain is worse on elevating and improved by lowering the leg (gravity helps the circulation)
Typically, venous ulcers:
- Occur in the gaiter area (between the top of the foot and bottom of the calf muscle)
- Are associated with chronic venous changes, such as hyperpigmentation, venous eczema and lipodermatosclerosis
- Occur after a minor injury to the leg
- Are larger than arterial ulcers
- Are more superficial than arterial ulcers
- Have irregular, gently sloping border
- Are more likely to bleed
- Are less painful than arterial ulcers
- Have pain relieved by elevation and worse on lowering the leg
Investigations
Ankle-brachial pressure index (ABPI) is used to assess for arterial disease. This is required in both arterial and venous ulcers.
Blood tests may help assess for infection (FBC and CRP) and co-morbidities (HbA1c for diabetes, FBC for anaemia and albumin for malnutrition).
Charcoal swabs may be helpful where infection is suspected, to determine the causative organism.
Skin biopsy may be required in patients where skin cancer (e.g., squamous cell carcinoma) is suspected as a differential diagnosis. This will require a two week wait referral to dermatology.
Management of Arterial Ulcers
The management of arterial ulcers is the same as peripheral arterial disease, with an urgent referral to vascular to consider surgical revascularisation. If the underlying arterial disease is effectively treated, the ulcer should heal rapidly. Debridement and compression are not used in arterial ulcers.
Management of Venous Ulcers
The management here is based on the NICE CKS (last updated January 2021). Patients may require referral to:
- Vascular surgery where mixed or arterial ulcers are suspected
- Tissue viability / specialist leg ulcer clinics in complex or non-healing ulcers
- Dermatology where an alternative diagnosis is suspected, such as skin cancer
- Pain clinics if the pain is difficult to manage
- Diabetic ulcer services (for patients with diabetic ulcers)
Patients require input from experienced nurses, such as the district nurses or tissue viability nurses. Good wound care involves:
- Cleaning the wound
- Debridement (removing dead tissue)
- Dressing the wound
Compression therapy is used to treat venous ulcers (after arterial disease is excluded with an ABPI).
Pentoxifylline (taken orally) can improve healing in venous ulcers (but is not licensed).
Antibiotics are used to treat infection.
Analgesia is used to manage pain (avoid NSAIDs as they can worsen the condition).
Last updated May 2021
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