A skin ulcer is an open sore in the skin. Pyoderma gangrenosum is an uncommon form of skin ulcers. It usually occurs on the lower legs, but can occur anywhere on the skin.
Side View of Skin Ulcer
Pyoderma gangrenosum is thought to be caused by a problem with the immune system. The immune system finds and attacks foreign items in the body like viruses. Sometimes the immune system attacks the body's own tissue. In this case, the immune system attacks an area of the skin.
Pyoderma gangrenosum is more likely to occur in people who have other underlying medical conditions, such as:
The main symptom of pyoderma gangrenosum is a painful skin ulcer. These ulcers may begin as small-irritated bumps from an injury. However, the ulcer can grow up to 7.9 in (inches) (20 cm [centimeters]). The ulcers often have purple edges that appear worn away.
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to a skin specialist. Pyoderma gangrenosum is diagnosed by its appearance. Your doctor will also want to rule out other conditions that can cause skin ulcers.
To look for other factors that could cause ulcers, your doctor may order:
- Sample of ulcer fluids—to look for infection or items that can cause infection
- Biopsy —a tissue sample examined under a microscope
- Blood tests
Talk with your doctor about the best treatment plan for you. Treatment options include:
Medications to treat pyoderma gangrenosum include:
- Oral corticosteroids
- Smaller ulcers may be treated with a topical steroid cream or an injection
You may need other medications to treat any underlying conditions
There are no current guidelines to prevent pyoderma gangrenosum.
American Academy of Dermatology
American Autoimmune Related Diseases Association
Canadian Dermatology Association
Canadian Institute for Health Information
Charles CA, Leon A, et al. Etanercept for the treatment of refractory pyoderma gangrenosum: a brief series. Int J Dermatol. 2007 Oct;46(10):1095-1099.
Pyoderma gangrenosum. DermNet NZ website. Available at: http://www.dermnetnz.org/reactions/pyoderma-gangrenosum.html. Accessed December 7, 2012.
Pyoderma gangrenosum. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T113752/Pyoderma-gangrenosum. Updated May 24, 2016. Accessed September 27, 2016.
Reguiaï Z, Grange F. The role of anti-tumor necrosis factor-alpha therapy in Pyoderma gangrenosum associated with inflammatory bowel disease. Am J Clin Dermatol. 2007;8(2):67-77.
Last reviewed December 2014 by Marcin Chwistek, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.