NORD gratefully acknowledges Mark Lebwohl, MD, Professor and Chairman, Department of Dermatology, The Mount Sinai School of Medicine, for assistance in the preparation of this report.
Pyoderma gangrenosum often begins as small, quick-spreading reddish or purple colored bumps or blisters. These small growths eventually develop into swollen, open sores (ulcerations) with a well-defined blue or violet-colored border. The size and depth of ulcerations vary. Ulcerations may spread, widen and deepen and may become extremely painful. In individual cases, ulcerations may continue to spread, remain unchanged, or heal without treatment (spontaneously).
Ulcerations can affect any part of the body and have been classified into four variants: classic, atypical/bullous, pustular, and vegetative.
Classic pyoderma gangrenosum most often occurs on the legs and is characterized by deep ulcerations. These lesions often begin as small pus-filled bumps (pustules) that enlarge and spread rapidly. This form of the disease is often very painful and may also affect the trunk, penis, head and neck areas.
Classic PG also occurs near surgical openings (stoma sites) in the body. This condition is referred to as peristomal pyoderma gangrenosum.
Atypical or bullous pyoderma gangrenosum is characterized by superficial blisters (bullae). This form of the disease most often affects the hands and is often associated with an underlying disorder especially hematological malignancy such as leukemia. Some cases that have been called atypical pyoderma gangrenosum actually represent Sweet syndrome.
Classic pyoderma gangrenosum is often characterized by the presence of pus and can begin with pustules. Pustular pyoderma gangrenosum is characterized by painful bumps (pustules) most often found on the arms and legs. These lesions eventually develop into ulcerations. This form is often associated with inflammatory bowel disease.
Vegetative pyoderma gangrenosum is characterized by chronic ulcerations that are not usually painful.
Additional findings sometimes associated with PG include fever, localized tenderness, joint pain (arthralgia), and a general feeling of ill health (malaise). PG may occur as a secondary characteristic of another disorder, most oftenulcerative colitis or Crohn’s disease.
The exact cause of pyoderma gangrenosum is unknown (idiopathic) although it is suspected to be an autoimmune disease. Autoimmune disorders are caused when the body’s natural defenses (e.g., antibodies) against foreign or invading organisms begin to attack healthy tissue for unknown reasons.
Approximately 50 percent of cases of pyoderma gangrenosum are associated with other disorders, especially the inflammatory bowel diseases ulcerative colitis or Crohn’s disease. Additional disorders associated with pyoderma gangrenosum include rheumatoid arthritis, acute and chronic myelogenous leukemia, myeloid metaplasia, and paraproteinemias.
In some cases the development of pyoderma gangrenosum follows surgery or trauma. This condition is known as pathergy.
Pyoderma gangrenosum affects women slightly more often than men. It occurs most often between the ages of 20 to 50 years. Infants or adolescents account for fewer than 4 percent of cases. One estimate places the incidence of PG at 1 in every 100,000 people in the United States.
No specific diagnostic tests exist for pyoderma gangrenosum. Diagnosis is made by excluding similar disorders based upon a thorough clinical evaluation, a detailed a patient history and a variety of tests such as surgical removal and microscopic evaluation of affected tissue (biopsy).
Treatment of PG consists of open wet dressings on the ulcers and topical application of anti-inflammatory creams and ointments such as corticosteroids. The skin must be protected from any other injury that could result in development of additional ulcers. In some cases, the grafting of new skin to the wound may be recommended once the inflammation is controlled.
Additional treatment of PG includes the administration of corticosteroid drugs such as methylprednisolone and prednisone. Corticosteroids may be administered by intramuscular injection or orally or by intralesional injection directly into the pyoderma gangrenosum.
According to some researchers, individuals with a past history of PG should receive preventive (prophylactic) treatment with corticosteroids before undergoing surgery because surgery may cause a recurrence of the disorder.
Immunosuppressive therapies (drugs that suppress the immune system) are sometimes used to treat people with pyoderma gangrenosum. Cyclosporine is effective for many patients. Azathioprine and cyclophosphamide are also immunosuppressive drugs that have been used to treat PG. In recent years drugs known as tumor necrosis factor inhibitors have been used very successfully to treat pyoderma gangrenosum. Infliximab and adalimumab have been most successful.
Antibacterial agents such as Dapsone may also be administered. In some cases surgical treatment of the underlying disorder such as ulcerative colitis has alleviate symptoms of pyoderma gangrenosum.
Additional treatment is symptomatic and supportive.
Researchers are studying the use of the orphan drug thalidomide as a treatment for pyoderma gangrenosum. Thalidomide can have severe effects on a developing fetus and must be administered with extreme caution. More studies are needed to determine the long-term safety and effectiveness of this treatment. For more information, contact:
7 Powder Horn Drive
Warren, NJ 07059
Tollfree: (888) 423-5436
Thalidomide is available in England under special license from Penn Pharmaceuticals of South Tredegar, South Wales.
Additional drugs that have been explored as potential treatments for individuals with PG include tacrolimus, ustekinumab, chlorambucil, clofazimine, mycophenolate mofetil, and intravenous immune globulin. More research is necessary to determine the long-term safety and effectiveness of these treatments for individuals with PG.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
For information about clinical trials sponsored by private sources, contact:
For information about clinical trials conducted in Europe, contact:
Lebwohl MG, Gohara M. Pyoderma Gangrenosum. In: NORD Guide to Rare Disorders. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:134-5.
Bennett JC, Plum F, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA: W.B. Saunders Co; 1996:2212.
Yamada T, et al., eds. Textbook of Gastroenterology. 2nd ed. Philadelphia, PA: J.B. Lippincott Company; 1995:955-56.
Champion RH, et al., eds. Textbook of Dermatology. 5th ed. Cambridge, MA: Blackwell Scientific Publications; 1992:1922-26.
Brooklyn TN, Dunnill GS. Shetty A, et al. Infliximab for the treatment of pyoderma gangrenosum: a randomized, double-blind placebo-controlled trial. Gut. 2006;55(4):505-9.
Vujnovich A. Clinical treatment options for peristomal pyoderma gangrenosum. Br J Nurs. 2005;14:S4-8.
Burton J. Case study: diagnosis and treatment of pyoderma gangrenosum. Br J Nurs. 2005;14:S10-3.
Reichrath J, Bens G, Bonowitz A, Tilgen W. Treatment recommendations for pyoderma gangrenosum: an evidence-based review of the literature based on more than 350 patients. J Am Acad Dermatol. 2005;53:273-83.
Nyback H, Olsen AG, Karlsmark T, Jemec GB. Topical therapy for peristomal pyoderma gangrenosum. J Cutan. Med Surg. 2004;8:220-3.
Hughes AP, et al. Clinical features and treatment of peristomal pyoderma gangrenosum. JAMA. 2000;284:1546-48.
Federman GL, et al. Recalcitrant pyoderma gangrenosum treated with thalidomide. Mayo Clin Proc. 2000;75:842-44.
Coors EA, et al. Pyoderma gangrenosum in a patient with autoimmune haemolytic anaemia and complement deficiency. Br J Dermatol. 2000;143:154-56.
MacKenzie D, et al. Pyoderma gangrenosum following breast reconstruction. Br J Plast Surg. 2000;53:441-43.
Hensley CD, et al. Neutrophilic dermatoses associated with hematologic disorders. Clin Dermatol. 2000;18:355-67.
Lyon CC, et al. Parastomal pyoderma gangrenosum: clinical features and management. J Am Acad Dermatol. 2000;42:992-1002.
Powell FC, et al. Pyoderma gangrenosum. Clin Dermatol. 2000;18:283-93.
Bennett ML, et al. Pyoderma gangrenosum. A comparison of typical and atypical forms with an emphasis on time to remission. Case review of 86 patients from 2 institutions. Medicine (Baltimore). 2000;79:37-46.
Hafner J, et al. Management of vasculitic leg ulcers and pyoderma gangrenosum. Curr Probl Dermatol. 1999;27:271-76.
V’lckova-Laskoska MT, Laskoski DS, Caca-Biljanovska NG, Darkoska JS. Pyoderma gangrenosum successfully treated with cyclosporin A. Adv Exp Med Biol. 1999;455:541-45.
Armstrong PM, et al. Pyoderma gangrenosum. A diagnosis not to be missed. J Bone Joint Surg Br. 1999;81:893-94.
von den Driesch P. Pyoderma gangrenosum: a report of 44 cases with follow-up. Br J Dermatol. 1997;137:1000-05.
Jackson JM. Pyoderma Gangrenosum.Medscape. http://emedicine.medscape.com/article/1123821-overview Updated: Nov 24, 2014. Accessed May 12, 2015.
Wollina U. Pyoderma Gangrenosum. Oprhanet. http://www.ojrd.com/content/2/1/19 April 15, 2007. Accessed May 12, 2015.
The information in NORD’s Rare Disease Database is for educational purposes only and is not intended to replace the advice of a physician or other qualified medical professional.
The content of the website and databases of the National Organization for Rare Disorders (NORD) is copyrighted and may not be reproduced, copied, downloaded or disseminated, in any way, for any commercial or public purpose, without prior written authorization and approval from NORD. Individuals may print one hard copy of an individual disease for personal use, provided that content is unmodified and includes NORD’s copyright.
National Organization for Rare Disorders (NORD)
55 Kenosia Ave., Danbury CT 06810 • (203)744-0100