Skin ulcers

Probability diagnosis

Traumatic ulcer

Decubitus (related to trauma)

Venous insufficiency

Arterial insufficiency

Mixed venous and aterial

Serious disorders not to be missed

Vascular:

• post-thrombophlebitis

• arterial insufficiency

• skin infarction (thrombolytic ulcer)

• vasculitis:

  • — rheumatoid arthritis, SLE, scleroderma

Infection:

• tropical ulcer

• tuberculosis

• Mycobacterium ulcerans

• postcellulitis

• chronic infected sinus

• AIDS

Malignant:

• squamous cell carcinoma

• Marjolin ulcer (SCC)

• basal cell carcinoma (rodent ulcer)

• malignant melanoma

• ulcerating metastases

Haematological:

• spherocytosis

• sickle cell anaemia

Neurotrophic:

• peripheral neuropathy (e.g. diabetes)

• peripheral nerve injuries (e.g. leprosy)

Other causes:

• pyoderma gangrenosum (diagnosis of exclusion)

• insect and spider bites

Masquerades checklist

Anaemia

Diabetes

Drugs (e.g. illicit drugs)

Is the patient trying to tell me something?

Consider artefactual ulceration, i.e. factitious.

Key history

A careful history helps determine the cause of the ulceration. Relevant history includes previous deep venous thrombosis or pulmonary embolism, diabetes, rheumatoid arthritis, inflammatory bowel disease, chronic skin ulcers and arterial insufficiency, including a history of intermittent claudication and ischaemic rest pain.

   A drug history is important, considering especially beta-blockers and ergotamine, which can compromise the arterial circulation, corticosteroids, and NSAIDs, which affect healing.

Key examination

• Any ulcer should be assessed for the following characteristics: site, shape, size, edge, floor, base, discharge, surrounding skin, regional lymph nodes

• Assess the circulation: venous and arterial

Key investigations

The following should be considered, according to the clinical findings:

• full blood count

• ESR, CRP

• random blood sugar

• rheumatoid factor tests

• duplex Doppler ultrasound

• swab for specific organisms

• biopsy, especially if SCC suspected.

Diagnostic tips

• The great majority of leg ulcers are vascular in origin due to arterial insufficiency or venous hypertension.

• If clinical findings don’t provide the diagnosis, ordering the ankle brachial index (ABI) is essential if pulses are not palpable to exclude arterial disease. Duplex Doppler ultrasound is the key investigation for venous disease.