Necrotizing Fasciitis (Flesh-Eating Bacteria)

Medically Reviewed by Carmelita Swiner, MD on November 12, 2022

What Is Flesh-Eating Bacteria (Necrotizing Fasciitis)?

Flesh-eating bacteria (necrotizing fasciitis) is a rare infection of the skin and tissues below it. It can be deadly if not treated quickly.

Necrotizing fasciitis spreads quickly and aggressively in an infected person. It causes tissue death at the infection site and beyond.

Every year, between 600 and 700 cases are diagnosed in the U.S. About 25% to 30% of those cases result in death. It rarely happens in children..

Flesh-Eating Bacteria Causes and Risk Factors

Necrotizing fasciitis is commonly caused by group A streptococcus (GAS) bacteria. That's the same type of bacteria that causes strep throat. But, several types of bacteria, such as staphylococcus and others, have also been linked to the disease.

Necrotizing fasciitis happens when these types of bacteria infect the superficial fascia, a layer of connective tissue below the skin.

Flesh-eating bacteria transmission

The bacteria that cause necrotizing fasciitis can enter the body through:

In some cases, it is unknown how the infection began. Once it takes hold, the infection rapidly destroys muscle, skin, and fat tissue.

Having a weakened immune system and certain diseases may make you more likely to get flesh-eating bacteria (necrotizing fasciitis). Health conditions that may raise your risk include:


Flesh-Eating Bacteria Symptoms

The early symptoms of an infection with flesh-eating bacteria usually appear within the first 24 hours of infection. Symptoms are similar to other conditions like the flu or a less serious skin infection. The early symptoms are also similar to common post-surgical complaints, such as:

Symptoms often include a combination of the following:

  • Increasing pain in the general area of a minor cut, abrasion, or other skin opening.
  • Pain that is worse than would be expected from the appearance of the cut or abrasion.
  • Redness and warmth around the wound, though symptoms can begin at other areas of the body.
  • Flu-like symptoms such as diarrhea, nausea, fever, dizziness, weakness, and general malaise.
  • Intense thirst due to dehydration.

More advanced symptoms happen around the painful infection site within 3 to 4 days of infection. They include:

  • Swelling, possibly along with a purplish rash
  • Large, violet-colored marks that turn into blisters filled with dark, foul-smelling fluid
  • Discoloration, peeling, and flakiness as tissue death (gangrene) happens

Critical symptoms, which often occur within 4 to 5 days of infection, include:


Flesh-Eating Bacteria Diagnosis

Flesh-eating bacteria (necrotizing fasciitis) affects the body quickly, making early diagnosis important to survival.

The doctor will examine you and review your symptoms. Having flesh-eating bacteria is a medical emergency, and if a doctor suspects you may have it, you’ll likely be admitted to a hospital and get tested there.

Tests to diagnosis flesh-eating bacteria (necrotizing fasciitis) include:

Blood tests. People with flesh-eating bacteria have high levels of white blood cells.

Tissue biopsy. You may need exploratory surgery to remove some of the tissue from the infected area. The tissue is sent to a lab to identify the particular bacteria that’s causing the infection. But you’ll be given some medicine to treat the infection before test results are back.

CT scan. A CT scan can show your doctor where fluid and pus are collecting in the body. It also shows the presence of gas bubbles under the skin, which helps confirm the diagnosis.

Household members and others who have had close contact with someone with necrotizing fasciitis should be tested for the disease if they have symptoms of an infection.

Flesh-Eating Bacteria Treatment

Patients infected with flesh-eating bacteria will undergo several types of treatment. The extent of treatment depends on the stage of the disease when treatment is started. The treatment includes:

  • Intravenous antibiotic therapy.
  • Surgery to remove damaged or dead tissue in order to stop the spread of infection.
  • Medications to raise blood pressure.
  • Amputations of affected limbs, in some cases.
  • Hyperbaric oxygen therapy may be recommended to preserve healthy tissue.
  • Cardiac monitoring and breathing aids.
  • Blood transfusions.
  • Intravenous immunoglobulin. This supports the body's ability to fight infection.


Flesh-Eating Bacteria Complications

Serious complications are common and may include:

  • Sepsis
  • Shock
  • Organ failure
  • Loss of an arm or leg due to amputation
  • Severe scarring
  • Death


Flesh-Eating Bacteria Prevention

Washing your hands with soap and water or using an alcohol-based hand sanitizer is one of the best steps you can take to prevent flesh-eating bacteria and other skin infections.

  • You can also prevent skin infections by taking these steps:
  • Always clean cuts and open wounds with soap and water.
  • After cleaning, cover an oozing, draining, or open wound with a clean, dry bandage.
  • Get treated by a doctor if you have a serious or deep wound, such as a puncture or gunshot.
  • Don’t go swimming or use a hot tub if you have an open wound or skin infection.

There’s no vaccine available to prevent flesh-eating bacteria infection.

Flesh-Eating Bacteria Outlook

Early diagnosis and rapid, aggressive treatment are critical when it comes to fighting this rare skin infection. Many people need more than one procedure to remove damaged, infected tissue. If you have red, swollen skin and it’s not going away, make an appointment with your doctor.

Show Sources


Medscape: "Necrotizing Fasciitis Clinical Presentation," "Emergent Management of Necrotizing Fasciitis."

Merck Manuals: "Necrotizing Skin Infections."

CDC: "Group A Streptococcal (GAS) Disease,” ”Type II Necrotizing Fasciitis,” “Necrotizing Fasciitis: All You Need to Know.”

National Necrotizing Fasciitis Foundation: "Necrotizing Fasciitis Factsheet."

American College of Chest Physicians: "Necrotizing Fasciitis and Deep Soft Tissue Infections in the ICU."

National Organization for Rare Diseases: “Necrotizing Fasciitis.”

Journal of the Formosan Medical Association: “Predisposing factors of necrotizing fasciitis with comparison to cellulitis in Taiwan: A nationwide population-based case–control study.”

Infectious Disease Clinics of North America: “Evaluation and Management of Necrotizing Soft Tissue Infections.”

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