Necrotizing Fasciitis (Flesh-Eating Disease)

What is necrotizing fasciitis?

Necrotizing fasciitis is a severe rapidly spreading bacterial infection that can cause death. The word “necrotizing” refers to something that causes the death of something else. The word “fasciitis” refers to inflammation of the fascia, which is the subcutaneous (under the skin) tissue that surrounds muscles and nerves and holds everything, including fat and blood vessels, in the correct position.

Necrotizing fasciitis is a form of necrotizing soft tissue infection (NSTI). Some people call necrotizing fasciitis or any NSTI the “flesh-eating disease.” Other NSTIs are necrotizing myositis and necrotizing cellulitis.

What are the different types of necrotizing fasciitis?

There are two types of necrotizing fasciitis: polymicrobial (also called Type I) and monomicrobial (also called Type II).

Polymicrobial necrotizing fasciitis is an infection caused by more than one type of bacteria, usually mixed anaerobic and aerobic bacteria. Monomicrobial necrotizing fasciitis is usually caused by group A Streptococcus or Staphylococcus aureus.

Who does necrotizing fasciitis affect?

Certain people are at greater risk of developing necrotizing fasciitis. These are people who have:

• Cuts in their skin or mucous membranes, including those made during surgical procedures.
• Obesity.
• Diabetes.
• Alcohol use disorder.
• Problems with your immune system or your vascular system.
• Cancer.
• Pregnancy.

How common is necrotizing fasciitis?

The number of cases of necrotizing fasciitis is estimated to be 0.3 to 15 per 100,000 people, but this is likely less than the true number. Between 2010 and now, the number of reported cases of necrotizing fasciitis caused by group A strep bacteria ranged from 700 to 1,200 per year. These numbers are likely to be lower than the actual total number of cases of necrotizing fasciitis. Up to 1 in 3 people with necrotizing fasciitis die from the infection.

What are the symptoms of necrotizing fasciitis?

Early symptoms of this condition include signs and symptoms that resemble those of the flu:

• Body aches.
• Fever.
• Chills.
• Nausea.
• Diarrhea.
• Severe pain at the site of injury.

The progression of necrotizing fasciitis is very quick. Later signs and symptoms include:

• Reddened and/or discolored skin.
• Swelling of affected tissues.
• Unstable blood flow.
• Blisters filled with bloody or yellowish fluid.
• Tissue death (necrosis).
• Low blood pressure.
• Sepsis.

It’s important to seek care quickly if you have developed signs and symptoms of necrotizing fasciitis as this infection spreads fast.

What causes flesh-eating disease?

The most common way to get necrotizing fasciitis is when bacteria invade your body through a cut in your skin, although it can happen if you have a trauma that doesn’t break the skin.

Ways that bacteria can enter your skin:

• Cuts, scrapes or burns.
• Insect bites.
• Wounds from needles and other things that cause puncture wounds.
• Surgery.
• While Group A strep bacteria are the most common cause of necrotizing fasciitis, you can also get it from many different types of bacteria, including bacteria that live in water.

How is necrotizing fasciitis diagnosed?

If your healthcare provider thinks you have flesh-eating disease, they may order diagnostic tests, including:

• Blood tests, such as a complete blood count.
• Culture of specimens taken from deep tissue.
• Tissue biopsy.
• Imaging tests, most likely a computed tomography (CT) scan.

Your provider will perform surgery to diagnose necrotizing fasciitis. They'll also perform surgery to examine your skin and tissues and remove dead tissue (a process called debriding).

How is necrotizing fasciitis treated?

Quick intervention is needed to control necrotizing fasciitis. You’ll require exploratory surgery to confirm the diagnosis of necrotizing fasciitis. Surgery is also required to remove dead tissue. It may take multiple surgeries to control the infection and remove all of the dead tissue. It takes an average of three surgeries to make sure all of the infection is gone. Your provider will also likely prescribe antibiotics and intravenous (IV) fluids. After surgery, you may need skin grafts or plastic surgery to help the wounds close completely.

What complications are related to necrotizing fasciitis?

Many complications of necrotizing fasciitis are serious. They may include:

• Scars.
• Loss of limbs (arms, legs, fingers, toes).
• Toxic shock syndrome.
• Sepsis.
• Death.

How can I prevent necrotizing fasciitis?

Currently, there isn’t a vaccine to prevent necrotizing fasciitis. To reduce your risk of bacterial skin infections, including necrotizing fasciitis, from developing:

• Try to avoid cuts, burns, scratches or bug bites.
• If you do have some type of wound, make sure to clean it with soap and water and then cover it with a clean bandage till it heals.
• See your healthcare provider for any deep or serious cuts or punctures.
• Keep your hands clean by washing with soap and water or using an alcohol-based antibacterial hand cleaning product.
• Don’t go into swimming pools, hot tubs or outside bodies of water if you have a break in your skin.

You should contact your healthcare provider if:

• You notice an area of discoloration and swelling that gets bigger quickly.
• You’re in a lot of pain.
• You develop a fever.

What can I expect if I have necrotizing fasciitis?

If you have this condition, your best outcome will come from receiving an accurate diagnosis and quick treatment with antibiotics combined with surgery to remove the dead tissue.

Necrotizing fasciitis (flesh-eating disease) gets worse quickly, destroying your tissue and causing things like organ failure. Even with treatment, 1 out of 3 people dies from this disease.

You may need more than one surgery to manage necrotizing fasciitis. You may have scarring.

When should I see my healthcare provider?

If you’ve been diagnosed with and treated for necrotizing fasciitis, and you aren’t getting better, contact your healthcare provider. Keep any follow-up appointments that your provider may schedule. If you’re taking antibiotics, make sure you take them as instructed.

What is the difference between gas gangrene and necrotizing fasciitis?

The disease gas gangrene (clostridial myonecrosis) happens to healthy tissue and leads to gas in the tissues. This gas is a waste product given off by germs. You may get gas in your tissues from either gas gangrene or Type I necrotizing fasciitis. However, the germs that cause each disease are different. Gas gangrene may also involve muscles.

Where is necrotizing fasciitis most commonly found?

Necrotizing fasciitis is most often found on your limbs, fingers and toes. The lower extremities (toes, feet, etc.) are more likely to develop necrotizing fasciitis, especially if you have diabetes.

Other areas that are affected by necrotizing fasciitis include the genitals and head and neck area.

Can you survive necrotizing fasciitis?

Yes, it’s possible to survive if you have necrotizing fasciitis. It’s important that diagnosis and treatment happen early.

Is necrotizing fasciitis contagious?

Necrotizing fasciitis rarely spreads from one person to another. Therefore, it's usually not necessary to give antibiotics to close contacts. But, in cases of severe infection, your provider might recommend your close contacts take preventive antibiotics.

How long does necrotizing fasciitis take to develop?

You may see symptoms of necrotizing fasciitis within 24 hours of getting scratched, bit, or cutting yourself. Necrotizing fasciitis gets worse quickly. Keep an eye out for areas that look swollen or red and that continue to get bigger.