Health Information Library

Overview

Pyoderma gangrenosum (pie-o-DUR-muh gang-ruh-NO-sum) is a rare condition that causes large, painful sores on the skin. The sores can develop quickly. Most often they appear on the legs.

The exact causes of pyoderma gangrenosum are unknown, but it appears to be a disorder of the immune system. People who have certain other conditions are at higher risk of pyoderma gangrenosum.

The condition usually clears up with treatment. But the sores often leave scars and can show up in new spots.

Symptoms

Pyoderma gangrenosum usually starts with a small bump on the skin. It might look like a spider bite. Within days it can turn into a large and painful open sore.

The sore usually appears on the legs but may develop anywhere on the body. Sometimes it appears around surgical sites. If you have two or more sores, they may grow and merge into one.

When to see a doctor

Talk with a healthcare professional if you develop a painful, rapidly growing skin wound.

Causes

No one knows the exact cause of pyoderma gangrenosum. It's often seen in people who have autoimmune diseases, such as ulcerative colitis, Crohn's disease and arthritis. And some studies suggest that it may be passed down through families.

If you have pyoderma gangrenosum, getting a cut or other skin wound can bring on new sores. The condition isn't an infection and it isn't contagious.

Risk factors

Certain factors may increase your risk of pyoderma gangrenosum, including:

• Being a woman between 20 and 50 years of age.
• Having an inflammatory bowel disease, such as ulcerative colitis or Crohn's disease.
• Having rheumatoid arthritis.
• Having a blood disorder, such as acute myelogenous leukemia or myelodysplasia.

Complications

Possible complications of pyoderma gangrenosum include infection, uncontrolled pain, scarring and and changes in skin color after the affected skin heals. This change in skin color is called postinflammatory hyperpigmentation when the skin darkens and postinflammatory hypopigmentation when the skin loses color. People with brown or Black skin have a higher risk of long-term skin color changes.

Prevention

You can't prevent the first instance of pyoderma gangrenosum. If you have the condition, you can help prevent new sores by protecting your skin from injury. Injury or trauma to the skin, including from surgery, can cause new sores to form.

It also may help to control any other condition you have that's related to pyoderma gangrenosum.

Diagnosis

Your healthcare professional will talk with you about your symptoms and medical history and conduct a physical exam. No test can confirm a diagnosis of pyoderma gangrenosum. But you may need tests to rule out other conditions that have similar symptoms. These may include blood tests, a chest X-ray, a colon exam or a skin biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab.

Correct and early diagnosis is key to effective treatment. You may be referred to a specialist in skin conditions. This type of doctor is called a dermatologist.

Treatment

Treatment of pyoderma gangrenosum is aimed at reducing swelling, controlling pain and helping skin sores heal. Medicines are the most common treatment. Treatment also might involve wound care and surgery. Your treatment depends on your health, how many sores you have, how deep they are and how fast they're growing.

Some people respond well to treatment with a combination of medicine taken by mouth, creams and injections. Sores can take weeks or months to heal, and it's common for new ones to develop.

Medicines

• Corticosteroids. The most common treatment for pyoderma gangrenosum is daily doses of corticosteroids. These drugs may be applied to the skin, injected into the wound or taken by mouth. The pill form is called prednisone. Using corticosteroids for a long time or in high doses may cause severe side effects. To avoid these side effects, steroids may be used only for short periods of time to control the sores. And other medicines that target the immune system may be used long term to control the disease. These are called steroid-sparing medicines or steroid-sparing drugs.
• Medicines that target the immune system. Some medicines can stop your immune system from attacking healthy tissues. Examples are the the steroid-sparing medicines cyclosporine, mycophenolate (Cellcept), immunoglobulins, dapsone, infliximab (Remicade) and tacrolimus (Protopic). Tacrolimus is a type of medicine called a calcineurin inhibitor. Steroid-sparing medicines might be applied to the wounds, injected or taken by mouth. These medicines also can have severe side effects.
• Pain medicine. Depending on the extent of your wounds, you may benefit from pain medicine, especially when your dressings are being changed.

Wound care

In addition to applying medicine to your wounds, a healthcare professional may cover them with a moist nonstick dressing and, perhaps, an elasticized wrap. You may be asked to keep the affected area raised. Follow instructions you receive for wound care.

Surgery

Because pyoderma gangrenosum can be made worse by cuts to the skin, surgery to remove dead tissue is not usually considered a good treatment option. Trauma to the skin may worsen existing sores or bring on new ones.

If sores are large and aren't healing, a skin graft may be an option. In this procedure, the surgeon attaches a piece of skin from somewhere else on your body over the open sores.

Coping and support

With treatment you're likely to recover from pyoderma gangrenosum. It may take a long time and you may feel stressed about whether new sores will form. You may find it helpful to talk with a counselor, medical social worker, or other people who have or had pyoderma gangrenosum. You may want to connect with a support group in person or online. Ask your healthcare professional for suggestions.

Preparing for an appointment

You're likely to first see your regular healthcare professional. You may then be referred to a doctor who specializes in skin conditions. This type of doctor is called a dermatologist.

Here's some information to help you get ready for your appointment.

What you can do

Before your appointment, make a list of:

• Symptoms you've been having and for how long.
• Key personal information, including any major stresses or recent life changes.
• All medicines, vitamins and supplements you take, including doses.
• Questions to ask your healthcare professional.

What to expect from your doctor

Your healthcare professional is likely to ask you a few questions, such as:

• When did you first begin experiencing symptoms?
• Does anything seem to improve your symptoms?
• What steps have you taken to treat this condition yourself?
• Have any of these measures helped?
• Have you ever been treated by a healthcare professional for this condition?
• If so, did you use any prescription treatments for this skin condition? If so, do you remember the name of the medicine and the dosage you were prescribed?
• Did you have a skin biopsy?