What is it?
Pyoderma gangrenosum is a chronic skin ulceration occurring usually on the legs but can appear anywhere on the body.

Pain may be apparent before the ulcers appear. They may also drain pus-like fluid but are not usually infected.

What is the cause?
The condition is usually associated with inflammatory bowel disease and is more common in ulcerative colitis (1-5%) than Crohn's disease (1-2%).

It is also often related to an injury, or following an injection in the affected area.

It can occur independently of active disease although pancolitis is found in 85% of patients with the condition.

What is the treatment?
Treatment of the underlying inflammatory bowel disease is often successful in resolving the skin lesions.

Medical treatments may be tried, such as:
• Topical antibiotics
• Corticosteroids
• Azathioprine
• Cyclosporin and other immunosuppressive drugs.

However, the lesions may return. Colectomy provides a cure in most cases of persistent, troublesome lesions.