Pyoderma gangrenosum usually starts with a small, red bump on your skin, which may resemble a spider bite. Within days, this bump can develop into a large, painful open sore.
The ulcer usually appears on your legs, but may develop anywhere on your body. Sometimes it appears around surgical sites. If you have several ulcers, they may grow and merge into one larger ulcer.
When to see a doctor
Talk to your doctor if you develop a painful, rapidly growing skin wound.
Pyoderma gangrenosum isn't infectious or contagious, but no one knows exactly what causes it. It's often associated with autoimmune diseases such as ulcerative colitis, Crohn's disease and rheumatoid arthritis. And some studies indicate that it may have a genetic component.
If you have pyoderma gangrenosum, new skin trauma, such as a cut or puncture wound, may trigger new ulcers.
Certain factors may increase your risk of pyoderma gangrenosum, including:
- Your age and sex. The condition is slightly more common among women. And it usually occurs between the ages of 40 and 50, though it can appear at any age.
- Having inflammatory bowel disease. People with a digestive tract disease such as ulcerative colitis or Crohn's disease are at increased risk of pyoderma gangrenosum.
- Having rheumatoid arthritis. People with rheumatoid arthritis are at increased risk of pyoderma gangrenosum.
- Having blood cancer. People with blood disorders (hematologic malignancies) are at increased risk of pyoderma gangrenosum.
Possible complications of pyoderma gangrenosum include:
- Uncontrolled pain
- Loss of mobility
Dec. 16, 2015
- Dabade TS, et al. Diagnosis and treatment of the neutrophilic dermatoses (pyoderma gangrenosum, Sweet's syndrome). Dermatologic Therapy. 2011;24:273.
- Miller J, et al. Pyoderma gangrenosum: A review and update on new therapies. Journal of the American Academy of Dermatology. 2010;62:646.
- AskMayoExpert. Pyoderma gangrenosum. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Shahi V, et al. Pyoderma gangrenosum associated with solid organ malignancies. International Journal of Dermatology. 2015;54:e351.
- Bolognia J, et al., eds. Neutrophilic dermatoses. In: Dermatology. 3rd ed. Philadelphia: Elsevier Saunders; 2012.
- Ferri FF. Pyoderma gangrenosum. In: Ferri's Clinical Advisor 2016. Philadelphia, Pa.: Mosby Elsevier; 2016. https://www.clinicalkey.com Accessed Sept. 24, 2015.
- Wolff K, et al. Neutrophil-mediated diseases. In: Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2013. http://www.accessmedicine.com. Accessed Sept. 29, 2015.
- Goldsmith LA, et al., eds. Pyoderma gangrenosum. In: Fitzpatrick's Dermatology in General Medicine. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com. Accessed Sept. 29, 2015.
- Stanislav N, et al. Postoperative pyoderma gangrenosum (PG): The Mayo Clinic experience of 20 years from 1994 through 2014. Journal of the American Academy of Dermatology. 2015;73:615.
- Braswel SF, et al. Pathophysiology of pyoderma gangrenosum (PG): An updated review. Journal of the American Academy of Dermatology. 2015;73:691.
- Cabalag MS, et al. Inpatient management of pyoderma gangrenosum: Treatments, outcomes and clinical implications. Annals of Plastic Surgery. 2015;74:354.
- AskMayoExpert. Skin grafts. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Stair-Buchmann ME, et al. Pyoderma gangrenosum: A difficult diagnosis best managed in a burn treatment center. Journal of Burn Care Research. 2015;36:3190.
- Armstrong DG, et al. Basic principles of wound management. http://www.uptodate.com/home. Accessed Sept. 30, 2015.
- Okhovat JP, et al. JAMA Dermatology Patient Page: Pyoderma gangrenosum. JAMA Dermatology. 2014;150:1032.
- DeFilipps EM, et al. The genetics of pyoderma gangrenosum and implications for treatment: A systematic review. British Journal of Dermatology. 2015;172:1487.
- AskMayoExpert. Skin ulcers. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.