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Disease Profile

Pyoderma gangrenosum

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset






Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable



Musculoskeletal Diseases; Skin Diseases


Pyoderma gangrenosum is a rare, destructive inflammatory skin disease of which a painful nodule or pustule breaks down to form a progressively enlarging ulcer. Lesions may occur either in the absence of any apparent underlying disorder or in association with other diseases, such as ulcerative colitis, Crohn's disease, polyarthritis (an inflammation of several joints together), gammopathy, vasculitis, leukemia, and other conditions.[1][2][3] Each year in the United States, pyoderma gangrenosum occurs in about 1 person per 100,000 people.[1]

Pyoderma gangrenosum belongs to a group of autoinflammatory skin diseases called neutrophilic dermatoses.[2][3][4] Neutrophils are a type of white blood cell or leukocyte which form an early line of defense against bacterial infections.[5] Ulcerations associated with pyoderma gangrenosum may occur after trauma or injury to the skin, a process called pathergy.[1][2] Treatment involves wound care and the use of anti-inflammatory agents, including antibiotics, corticosteroids, immunosuppressants, and biologics.[1][2][3][4]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Joint pain
Muscle ache
Muscle pain

[ more ]

Muscle inflammation
Skin ulcer
Open skin sore
30%-79% of people have these symptoms
Atrophic scars
Sunken or indented skin due to damage
Increased circulating antibody level
Inflammation of the large intestine
Myeloid leukemia
Rheumatoid arthritis
5%-29% of people have these symptoms
Abnormal blistering of the skin
Blistering, generalized

[ more ]

Skin vesicle


Although antibiotics are often prescribed prior to having a correct diagnosis (and may be continued if there is a secondary infection or surrounding cellulitis), antibiotics are generally not helpful for treating uncomplicated cases of pyoderma gangrenosum.[3] The best documented treatments are systemic corticosteroids and cyclosporin A.[4] Smaller ulcers may be treated with strong topical steroid creams, steroid injections, special dressings, oral anti-inflammatory antibiotics, and/or other therapies. More severe cases typically require immunosuppressive therapy (used to decrease the body's immune responses). Combinations of steroids with cytotoxic drugs may be used in resistant cases. There has reportedly been rapid improvement of pyoderma gangrenosum with use of antitumor necrosis alpha therapy (such as infliximab), which is also used to treat Crohn's disease and other conditions.[2][3][4] Skin transplants and/or the application of bioengineered skin is useful in selected cases as a complementary therapy to immunosuppressive treatment.[4] The use of modern wound dressings is helpful to minimize pain and the risk of secondary infections.[3][4] Treatment for pyoderma gangrenosum generally does not involve surgery because it can result in enlargement of the ulcer; however, necrotic tissue (dying or dead tissue) should be gently removed.[3]

More detailed information about the treatment of pyoderma gangrenosum is available on the Treatment and Medication pages of Medscape Reference.


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
      • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
      • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

        In-Depth Information

        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Pyoderma gangrenosum. Click on the link to view a sample search on this topic.


          1. J Mark Jackson. Pyoderma Gangrenosum. Medscape Reference. April 26, 2016; https://emedicine.medscape.com/article/1123821-overview.
          2. Wingfield E. Rehmus. Pyoderma Gangrenosum. Merck Manual Professional Version. November 2013; https://www.merckmanuals.com/professional/dermatologic-disorders/hypersensitivity-and-inflammatory-disorders/pyoderma-gangrenosum?qt=Pyoderma%20gangrenosum&alt=sh.
          3. Amanda Oakley. Pyoderma gangrenosum. DermNet NZ. September 2015; https://www.dermnet.org.nz/reactions/pyoderma-gangrenosum.html.
          4. Uwe Wollina. Pyoderma gangrenosum. Orphanet. April 2007; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=48104.
          5. Neil K. Kaneshiro. Neutrophils. MedlinePlus. November 19, 2015; https://medlineplus.gov/ency/imagepages/19864.htm.

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