Necrotizing soft tissue infection

Answer 1

Definition

Necrotizing soft tissue infection is a rare but very severe type of bacterial infection that can destroy the muscles, skin, and underlying tissue. Necrotizing refers to something that causes tissue death.

Alternative Names

Necrotizing fasciitis; Fasciitis - necrotizing; Flesh-eating bacteria; Soft tissue gangrene; Gangrene - soft tissue

Causes, incidence, and risk factors

Many different types of bacteria can cause this type of infection. A very severe and usually deadly form of necrotizing soft tissue infection is due to Streptococcus pyogenes, which is sometimes called "flesh-eating bacteria."

Necrotizing soft tissue infection develops when the bacteria enters the body, usually through a minor cut or scrape. The bacteria begins to grow and release harmful substances (toxins) that:

• Directly kill tissue
• Interfere with the blood flow to the tissue
• Break down materials in the tissue, which rapidly spreads the bacteria, leading to widespread effects such as shock

Symptoms

The first sign of infection may be a small, reddish, painful spot or bump on the skin. This quickly changes to a very painful bronze- or purple-colored patch that grows rapidly. The center may become black and die off. The skin may break open and ooze fluid. The wound may quickly grow in less than an hour.

Symptoms may include general ill feeling, fever, sweating, chills, nausea, dizziness, profound weakness, and finally shock. Without treatment, death can occur rapidly.

Signs and tests

How the skin and tissue look can help the doctor diagnose a necrotizing soft tissue infection. Often a patient will be diagnosed in the operating room by a surgeon. Imaging tests, such as CT scans, are sometimes helpful.

Tests performed on blood, fluids, or tissue from the area may determine the bacteria that is causing the infection.

Treatment

Powerful, broad-spectrum antibiotics must be given immediately through a vein (IV). Surgery is required to open and drain infected areas and remove dead tissue. Sometimes donor immunoglobulins (antibodies) are given by vein to help fight the infection.

Skin grafts may be needed after the infection goes away. If an arm or leg infection cannot be controlled, amputation of the limb may be considered.

If the bacteria is determined to be an oxygen-avoiding organism (anaerobe), the patient may receive hyperbaric oxygen therapy. This involves placing the patient in a chamber that delivers 100% oxygen at high pressure.

Expectations (prognosis)

How well a patient does depends on:

• How fast the diagnosis was obtained
• The type of bacteria causing the infection
• How quickly the infection spreads
• How well the antibiotics work

Scarring and deformity are common with this type of disease. The Death Rate is high, even with aggressive treatment and powerful antibiotics. Untreated, the infection spreads and causes death.

Complications

• Local spread of infection, progressive tissue damage
• Systemic spread of infection, sepsis, shock
• Scarring and disfigurement
• Functional loss of an arm or leg
• Death

Calling your health care provider

This disorder is severe and may be life threatening, so contact your health care provider immediately if symptoms of infection occur around a skin injury, including:

• Drainage of pus or blood
• Fever
• Pain
• Redness
• Swelling

Prevention

Always clean the skin thoroughly after a cut, scrape, or other skin injury.

Answer 2

Definition

Necrotizing soft tissue infection is a rare but very severe type of bacterial infection. It can destroy the muscles, skin, and underlying tissue. The word "necrotizing" refers to something that causes body tissue to die.

Alternative Names

Necrotizing fasciitis; Fasciitis - necrotizing; Flesh-eating bacteria; Soft tissue gangrene; Gangrene - soft tissue

Causes, incidence, and risk factors

Many different types of bacteria can cause this infection. A very severe and usually deadly form of necrotizing soft tissue infection is due to Streptococcus pyogenes, which is sometimes called "flesh-eating bacteria."

Necrotizing soft tissue infection develops when the bacteria enters the body, usually through a minor cut or scrape. The bacteria begins to grow and release harmful substances (toxins) that kill tissue and affect blood flow to the area. As the tissue dies, the bacteria enters the blood and rapidly spreads throughout the body.

Symptoms

Symptoms include:

• Small, red, painful lump or bump on the skin
• Changes to a very painful bruise-like area and grows rapidly, sometimes in less than an hour
• The center may become black and die
• The skin may break open and ooze fluid

Other symptoms can include:

• Feeling ill
• Fever
• Sweating
• Chills
• Nausea
• Dizziness
• Weakness
• Shock

Signs and tests

Your doctor or nurse may diagnose this condition by looking at your skin. You may be diagnosed in an operating room by a surgeon.

Tests that may be done include:

• CT scan
• Blood tests
• Skin tissue biopsy

Treatment

Immediate treatment is needed to prevent death. Treatment includes:

• Powerful, broad-spectrum antibiotics given immediately through a vein (IV)
• Surgery to drain the sore and remove dead tissue
• Special medicines called donor immunoglobulins (antibodies) to help fight the infection in some cases

Other treatments may include:

• Skin grafts after the infection goes away to help your skin heal and look better
• Amputation if the disease spreads through an arm or leg
• 100% oxygen at high pressure (hyperbaric oxygen therapy) for certain types of bacterial infections

Expectations (prognosis)

How well you do depends on:

• Your overall health (especially if you have Diabetes)
• How fast you were diagnosed and how quickly you received treatment
• The type of bacteria causing the infection
• How quickly the infection spreads
• How well treatment works

This disease commonly causes scarring and skin deformity.

Death can occur rapidly without proper treatment.

Complications

• Infection spreads throughoug body, causing a blood infection (sepsis), which can be deadly
• Scarring and disfigurement
• Loss of your ability to use an arm or leg
• Death

Calling your health care provider

This disorder is severe and may be life threatening, so contact your health care provider immediately if symptoms of infection occur around a skin injury, including:

• Drainage of pus or blood
• Fever
• Pain
• Redness
• Swelling

Prevention

Always clean the skin thoroughly after a cut, scrape, or other skin injury.

Reviewed By

Review Date: 11/22/2011

Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.