Differential diagnosis of leg ulcers

Author: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, February 2016.

What is a leg ulcer?

A chronic leg ulcer is defined as full thickness skin loss for > 3 months. At times, it can be difficult to determine the correct diagnosis of a leg ulcerAt least 15% of leg ulcers are of mixed aetiology. It is essential to take a thorough medical history and to examine the patient carefully, looking for local and systemic clues to diagnosis.

Contributing factors to leg ulceration

Whatever the primary cause of the ulcer, there are often other factors that contribute to the poor healing of ulcers. These include:

Immediate cause of ulceration

An ulcer often begins with:

A chronic infection can also be responsible for ulceration, particularly:

Infection is identified by swabs and biopsy samples sent for bacterial and fungal microscopy and culture.

Common reasons for leg ulceration

Chronic venous insufficiency (70%)

Chronic arterial insufficiency (10%)

Neuropathic ulceration

Diabetic ulcer

Pressure ulcers

Hypertensive ulcer

Skin cancer

Inflammatory causes of leg ulceration and vascular occlusion

Inflammatory causes of leg ulceration can be difficult to diagnose and difficult to treat.

If considering an inflammatory cause of leg ulceration, diagnostic tests may involve:

Pyoderma gangrenosum

Small vessel vasculitis

Medium vessel vasculitis

Rheumatoid ulceration

Necrobiosis lipoidica

Systemic sclerosis

Livedoid vasculopathy

Warfarin induced skin necrosis

Heparin induced necrosis

Other coagulopathy

Cholesterol embolism

Cholesterol emboli




Levamisole-adulterated cocaine vasculopathy

Levamisole-adulterated cocaine can result in a combination of:

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