Red flag symptoms - Leg ulcers

The causes of leg ulcers, examination, initial investigations and red flag symptoms warranting further investigation.

Ulcer location: clue to aetiology (Photograph: SPL)
Ulcer location: clue to aetiology (Photograph: SPL)

Red flag symptoms

  • Persistent non healing ulcer despite intensive district nurse involvement
  • Absence of peripheral pulses
  • Symptoms suggestive of intermittent claudication
  • Presence of cellulitis
  • Increasing pain suggesting osteomyelitis

Leg ulcers are commonly managed by district nurses or practice nurses, however an understanding of their causes is essential for GPs and other members of the primary healthcare team.

An ulcer is defined as a full thickness loss of epithelium. Chronic venous leg ulceration has an estimated prevalence of between 0.1% and 0.3% in the United Kingdom.1


Ask how long the ulcer has been present, and whether or not there is any pain. Find out whether there is a strong vascular history, for example, diabetes, MI, peripheral vascular disease or a history of DVT or varicose veins.

Patients with known CVD are are at higher risk of arterial ulceration. If an arterial ulcer is suspected, then a history of peripheral vascular disease must be established.

A history of diabetes and absence of pain may imply a neuropathic component.

Diabetes can lead to macrovascular and microvascular complications leading to poor perfusion of tissues and thus ulceration. There may be multifactorial reasons for the leg ulcers - for example, a diabetic foot ulcer maybe both neuropathic and arterial.

Consider any treatments that have been tried so far and whether they have helped. Be alert to the non-healing, persistent, worsening ulcer. This may require a biopsy.

However, the aetiology may be clear, for example with a traumatic ulcer, and only district nurse input may be needed.


Inspect the feet carefully. Note whether there is any atrophy or hair loss indicative of poor perfusion, which would suggest that the ulcer is arterial. Eczematous change may be the result of venous eczema.

The location of the leg ulcers may give a clue to the aetiology. Venous ulcers tend to be confined to the 'gaiter' area of the lower leg whilst both arterial and neuropathic ulcers tend to be over pressure points.

Measure the ulcer and look for any sign of infection. A well demarcated ulcer suggests ischaemic aetiology, an irregular ulcer suggests a venous aetiology. If the ulcer is over a bony prominence, always consider osteomyelitis.

Check the foot pulses and if these are absent, consider a more detailed examination of lower limb pulses. Check the temperature of the feet along with the capillary refill time.

A cold foot, increased capillary refill time and absent foot pulses may require intervention from a vascular surgeon and highlight the need for a more detailed cardiovascular review of the patient. In this case, perform Doppler studies and measure ankle brachial pressure index (ABPI). However be aware that a normal ABPI measurement can occur in patients with diabetes.

If an ulcer is getting worse after compression bandaging, then the diagnosis needs to be reconsidered as the cause is likely to be arterial.

Possible causes
  • Venous stasis/hypertension
  • Arterial insufficiency
  • Neuropathy
  • Vasculitis, for example, rheumatoid, lupus, polyarteritis nodosa
  • Neoplastic causes such as basal cell or squamous cell carcinoma
  • Trauma such as burns
  • Haematological problems such as leukaemia
  • Infection such as cellulitis
  • Metabolic causes, such as gout


Generally minimal investigations are required but a cardiovascular risk assessment may be necessary. An X-ray may be necessary to exclude osteomyelitis. If malignancy is suspected, a biopsy should be arranged. Investigations including ESR should be arranged if vasculitis is thought to be the cause.

Other blood tests may include HbA1C and cholesterol. You may also wish to consider ABPI measurement depending on the history and location of the ulcer.

Advice for patients with diabetes

Diabetic foot care is crucial for those living with diabetes and leaflets are available on and the importance of good foot care should be emphasised at every annual review. Foot examination is a crucial part of the annual review.

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  1. SIGN guideline 120 Management of venous leg ulcers 2010

This is an updated version of an article that first appeared in January 2011

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