WOMEN'S HEALTH Hair/Nails/Skin • Corns and calluses • Diaper rash • Nail fungus • Shingles • Ingrown toenails • Moles • Acne • Psoriasis • Hair loss • Sweating and body odor • Rosacea • Hives and angioedema • Athlete's foot • Dermatitis/Eczema • Cold sore • Common warts • Cellulitis • Anal itching • Dandruff • Impetigo • Boils and carbuncles • Ringworm of the body • Jock itch • Plantar warts • Folliculitis • Dry skin • Actinic keratosis • Bedsores (Pressure sores) • Vitiligo • Lipoma • Tinea versicolor • Acanthosis nigricans • Molluscum contagiosum • Neurodermatitis (lichen simplex chronicus) • Morphea • Pityriasis rosea • Lichen nitidus • Bullous pemphigoid • Pyoderma gangrenosum • Lichen sclerosus • Ichthyosis vulgaris • Pilonidal cyst • Pemphigus • Sweet's syndrome • Sacral dimple • Dermatographia • Keratosis pilaris • Poison ivy rash • Lichen planus • Granuloma annulare • Dyshidrosis • Hidradenitis suppurativa • Henoch-Schonlein purpura • Hemangioma

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Pyoderma gangrenosum is a condition that causes large, painful sores (ulcers) to develop on your skin, most often on your legs.

It's not certain what causes pyoderma gangrenosum, but it may be related to a disorder of the immune system. About half the people with pyoderma gangrenosum have an underlying chronic health condition.

Pyoderma gangrenosum is rare. Effective treatment for pyoderma gangrenosum is available, but in some cases, the ulcers may leave scars. Early diagnosis and therapy reduces your risk of scarring. Occasionally, pyoderma gangrenosum may return.

The first sign of pyoderma gangrenosum is one or more small, red bumps on your skin that resemble spider bites. Over time, the bumps expand to form painful, open sores with reddish-purple borders. The ulcers usually appear on your legs but may develop anywhere on your body. Other symptoms you might experience include achy joints or pain in your bones and tiredness.

There's no specific cause of pyoderma gangrenosum. However, skin trauma, such as a cut or puncture wound, can result in new ulcers forming in people that have this skin disorder.

Pyoderma gangrenosum is most common in people in their 40s and 50s but can occur at any age. It's also associated with the following conditions:

• Ulcerative colitis. This disease of the large intestine causes chronic inflammation of your large intestine.
• Crohn's disease. Like ulcerative colitis, Crohn's disease causes long-term inflammation in the intestine but can occur anywhere along your digestive tract.
• Rheumatoid arthritis. Rheumatoid arthritis refers to a condition in which the thin membranes surrounding your joints become irritated and inflamed.
• Hepatitis. This condition causes your liver to become inflamed. The cause of hepatitis may be a virus or a disorder of your immune system.

Talk to your doctor if you develop an unexplained blistering on your skin, an itchy rash or a sore that's slow to heal. If you have pyoderma gangrenosum, you'll likely see a doctor who is specially trained in treating skin conditions (dermatologist).

The sudden appearance of unexplainable ulcers on your skin is the first indication that you may have pyoderma gangrenosum. In order to rule out a bacterial infection or some other cause, your doctor may examine a culture sample from your skin or a sample of your skin under a microscope (biopsy).

You'll likely also have a complete physical exam, including blood tests, to determine whether you have an underlying health condition that's associated with pyoderma gangrenosum.

Ulcers caused by pyoderma gangrenosum are usually raw and tender. You may find you'll need to decrease your activities until the sores heal. Sometimes the ulcers may leave scars.

One category of drugs used to treat pyoderma gangrenosum, called immunosuppressants, subdues your immune system. Using immunosuppressants for a long time may increase your likelihood of developing certain infections and cancers.

If you have an underlying disease associated with pyoderma gangrenosum, treating that condition may help control the ulcers. Other treatment options include:

• Wound care. Your doctor may recommend that you apply antibacterial ointments to the ulcers to help prevent infection or wrap your skin in a protective layer of gauze.
• Corticosteroids. Corticosteroids help relieve inflammation. Usually pyoderma gangrenosum is treatable with oral corticosteroids, but in some cases the type that you can spread on your skin (topical) may be used.
• Immunosuppressants. These drugs help calm the autoimmune response in your skin, which reduces inflammation.
• Surgery. Doctors don't commonly use surgery as a treatment option because trauma to the skin may worsen existing ulcers or stimulate new ones to develop. If the ulcers on your skin are large and need help with healing, your doctor may surgically attach a piece of real or artificial skin over the open sores. Doctors perform surgery only once all of the inflammation has improved.

As your skin heals, you'll likely taper off the corticosteroids or immunosuppressants. You can expect your skin to recover several months after beginning therapy. Without treatment, the ulcers may widen, remain the same or slowly heal.

You can't prevent pyoderma gangrenosum. If you have the condition, try to avoid injuring your skin. Trauma can provoke new ulcers to form.

If you have pyoderma gangrenosum, it's important to treat your skin gently. Apply bandages and soothing creams as directed by your doctor. Careful treatment helps reduce the risk of scarring. Also, remember to apply sunscreen with a sun protection factor (SPF) of 15 or greater before you head outdoors.