Streptococcal infections that start in the skin can sometimes spread elsewhere, resulting in a rare but potentially life-threatening condition called necrotizing fasciitis, sometimes referred to as flesh-eating bacterial syndrome. S. pyogenes is one of several species that can cause this rare but potentially-fatal condition; others include Klebsiella, Clostridium, Escherichia coli, S.aureus, and Aeromonas hydrophila.

Necrotizing fasciitis occurs when the fascia, a thin layer of connective tissue between the skin and muscle, becomes infected. Severe invasive necrotizing fasciitis due to Streptococcus pyogenes occurs when virulence factors that are responsible for adhesion and invasion overcome host defenses. S. pyogenes invasins allow bacterial cells to adhere to tissues and establish infection. Bacterial proteases unique to S. pyogenes aggressively infiltrate and destroy host tissues, inactivate complement, and prevent neutrophil migration to the site of infection. The infection and resulting tissue death can spread very rapidly, as large areas of skin become detached and die. Treatment generally requires debridement (surgical removal of dead or infected tissue) or amputation of infected limbs to stop the spread of the infection; surgical treatment is supplemented with intravenous antibiotics and other therapies.

Necrotizing fasciitis does not always originate from a skin infection; in some cases there is no known portal of entry. Some studies have suggested that experiencing a blunt force trauma can increase the risk of developing streptococcal necrotizing fasciitis.

Necrotizing fasciitis (NECK-re-tie-zing FASH-e-i-tis) is a rare bacterial infection that spreads quickly in the body and can cause death.

Accurate diagnosis, rapid antibiotic treatment, and prompt surgery are important to stopping this infection.

See a doctor right away if your skin becomes red, warm, swollen, or very painful soon after an injury or surgery.

Group A strep thought to be most common cause

There are many types of bacteria that can cause the “flesh-eating disease” called necrotizing fasciitis. Public health experts believe group A Streptococcus (group A strep) are the most common cause of necrotizing fasciitis. This web page only focuses on necrotizing fasciitis caused by group A strep bacteria.

Bacteria that live in water, including Vibrio vulnificus, can also cause necrotizing fasciitis. Learn about Vibrio wound infections.

How you get necrotizing fasciitis

The bacteria most commonly enter the body through a break in the skin. Different breaks in the skin can include:

• Cuts and scrapes
• Burns
• Insect bites
• Puncture wounds (including those due to intravenous [IV] drug use)
• Surgical wounds

However, people can also get necrotizing fasciitis after blunt trauma (an injury that does not break the skin).

Necrotizing fasciitis is rarely contagious

Most cases of necrotizing fasciitis occur randomly. It is very rare for someone with necrotizing fasciitis to spread the infection to other people. For this reason, doctors usually do not give preventive antibiotics to close contacts of someone with necrotizing fasciitis.

What’s in a Name?

Necrotizing means causing the death of tissues. Fasciitis means inflammation of the fascia (the tissue under the skin that surrounds muscles, nerves, fat, and blood vessels).

Symptoms can often be confusing and develop quickly

The infection often spreads very quickly.

Early symptoms of necrotizing fasciitis can include:

• A red, warm, or swollen area of skin that spreads quickly
• Severe pain, including pain beyond the area of the skin that is red, warm, or swollen
• Fever

See a doctor right away if you have these symptoms after an injury or surgery. Even though minor illnesses can cause symptoms like these, people should not delay getting medical care.

Later symptoms of necrotizing fasciitis can include:

• Ulcers, blisters, or black spots on the skin
• Changes in the color of the skin
• Pus or oozing from the infected area
• Dizziness
• Fatigue (tiredness)
• Diarrhea or nausea

Some people are at increased risk

While anyone can get necrotizing fasciitis, it is rare.

Other health factors

Most people who get this illness have other health problems that may lower their body’s ability to fight infections. Some conditions that weaken the body’s immune system include:

• Diabetes
• Kidney disease
• Cirrhosis (scarring) of the liver
• Cancer

Diagnosis can be difficult and acting fast is key

There are many infections that look similar to necrotizing fasciitis in the early stages, which can make diagnosis difficult. In addition to looking at the injury or infection, doctors can diagnose necrotizing fasciitis by:

• Performing a biopsy (taking a tissue sample)
• Looking at bloodwork for signs of infection and muscle damage
• Looking at imaging (CT scan, MRI, ultrasound) of the damaged area

However, it is important to start treatment as soon as possible. Therefore, doctors may not wait for test results if they think a patient might have necrotizing fasciitis.

Prompt treatment is key

Necrotizing fasciitis is a very serious illness that requires care in a hospital. Antibiotics and surgery are typically the first lines of defense if a doctor suspects a patient has necrotizing fasciitis.

Antibiotics

To try to stop the infection, doctors give antibiotics through an IV, which allows medicine to flow into a vein.

Sometimes, however, antibiotics cannot reach all the infected areas because the bacteria have killed too much tissue and reduced blood flow. When this happens, doctors must surgically remove the dead tissue.

Surgery

Since necrotizing fasciitis can spread so rapidly, patients often must get surgery done very quickly. It is not unusual for someone with necrotizing fasciitis to end up needing multiple surgeries. In serious cases, the patient may need a blood transfusion.

Serious complications are common

Necrotizing fasciitis can lead to

• Sepsis
• Shock
• Organ failure

It can also result in life-long complications from loss of limbs or severe scarring due to surgically removing infected tissue.

Looking at data from the most recent five years:

• Even with treatment, up to 1 in 5 people with necrotizing fasciitis died from the infection
• Up to 1 in 3 people who got both necrotizing fasciitis and streptococcal toxic shock syndrome at the same time died from their infections

Prevent necrotizing fasciitis

There are no vaccines to prevent group A strep infections, but there are things you can do to help protect yourself and others.

To help prevent group A step infections, you should:

• Wash your hands often
• Clean and care for wounds

Clean and care for wounds

Protect wounds and infections

If you have an open wound or skin infection, avoid spending time in:

• Hot tubs
• Swimming pools
• Natural bodies of water (e.g., lakes, rivers, oceans)

Care for fungal infections

Care for fungal infections like athlete’s foot to help prevent group A strep infections. Learn about athlete’s foot (ringworm).

Anyone can develop necrotizing fasciitis. The most common cause is group A Streptococcus. Other types of bacteria that can cause necrotizing fasciitis include Klebsiella, Clostridium, and Escherichia coli. Approximately one-half of necrotizing fasciitis cases caused by streptococcal bacteria occur in young and otherwise healthy individuals. Although necrotizing fasciitis most frequently develops after trauma that causes a break in the skin, it can also develop after minor trauma that occurs without a break in the skin. Necrotizing fasciitis can occur as a complication of surgery; it can also occur at the site of a relatively minor injury such as an insect bite or an injection. In addition, underlying illnesses that weaken the immune systemmay increase the risk of necrotizing fasciitis. Some studies suggest a possible relationship between the use of nonsteroidal anti-inflammatory medications (NSAIDs) during varicella infections and the development of necrotizing fasciitis.

Symptoms often begin within hours of an injury and typically include intense pain and tenderness over the affected area. The pain is often severe and may resemble that of a torn muscle. Early symptoms may be mistaken for the flu and can include fever, sore throat, stomach ache, nausea, diarrhea, chills, and general body aches. The patient may notice redness around the area that spreads quickly; the affected area can eventually become swollen, shiny, discolored, and hot to the touch. In addition, ulcers or blisters may develop. If the infection continues to spread, the patient may experience dehydration, high fever, fast heart rate, and low blood pressure. Pain may actually improve as tissues and the nerves are destroyed. As the infection spreads, vital organs may be affected and the patient may become confused or delirious. If not successfully treated, necrotizing fasciitis can lead to shock and eventual death.

Accurate and prompt diagnosis, treatment with intravenous (IV) antibiotics, and surgery to remove dead tissueare vital in treating necrotizing fasciitis. As the blood supply to the infected tissue becomes impaired, antibiotics often cannot penetrate the infected tissue. Therefore, surgery to remove the dead, damaged, or infected tissue is the primary treatment for necrotizing fasciitis. Early surgery may minimize tissue loss, eliminating the need for amputation of the infected body part. The choice of antibiotics will likely depend on the particular bacteria involved. In addition, supplemental oxygen, fluids, and medicines may be needed to raise the blood pressure. Hyperbaric oxygen therapy and IV immunoglobulin may also be considered, but their use in patients with necrotizing fasciitis is controversial.

If diagnosed and treated early, most patients will survive necrotizing fasciitis. If tissue loss is significant, skin grafting may be necessary. In some patients, amputation of the affected area is required. Up to 25% of patients will die from necrotizing fasciitis, due to complications such as kidney failure, blood poisoning (septicemia), and organ failure. The particular type of bacteria, the health of the patient, the location of the infection, and the speed of treatment can all influence the outcome.