Necrotizing fasciitis is a serious but rare bacterial infection. It is also known as flesh-eating disease.
Necrotizing fasciitis happens when bacteria enter a wound and cause a skin infection that can spread quickly through the deep tissues in the body.
It is rare in the United States, affecting about 0.4 in every 100,000 people.
In this article, we take a close look at necrotizing fasciitis, including its causes, symptoms, diagnosis, and recovery. We also discuss how to prevent and treat this infection.
Necrotizing fasciitis is a rare but serious bacterial infection. It occurs when bacteria destroy tissues deep inside the body.
The word “necrotizing” means that the infection causes the death of bodily tissue, while “fasciitis” refers to the inflammation of deep tissues. These include the fascia, which are the tissues surrounding the muscles, nerves, and blood vessels.
Necrotizing fasciitis is a very serious condition, and complications — which can include sepsis, shock, and organ failure — are common. Even with treatment, as many as 1 in 3 people may die from the infection.
However, an accurate, early diagnosis and rapid antibiotic treatment can stop this infection.
Many types of bacteria can cause necrotizing fasciitis. The most common is group A Streptococcus, the same bacterium that causes strep throat.
Group A Streptococcus is also responsible for some skin infections and some rare, severe illnesses, including toxic shock syndrome.
Other bacteria that can cause necrotizing fasciitis include Klebsiella, Clostridium, Escherichia coli, and some water-based bacteria, such as Vibrio vulnificus.
The bacteria can enter via breaks in the skin, which may result from:
- cuts or scrapes
- insect bites
- surgical wounds
In the U.S., group A Streptococcus has caused 700–1,200 cases of necrotizing fasciitis each year since 2010.
On rare occasions, people can get this infection without sustaining an injury that breaks the skin.
The person may get exposed to the bacteria through direct contact with a carrier, or the bacteria may already be present on the body.
Necrotizing fasciitis infections can arise suddenly and spread quickly. The symptoms may begin within hours of the injury.
Early signs and symptoms of necrotizing fasciitis include:
- flu-like symptoms, such as fever, sore throat, nausea, diarrhea, body aches, and chills
- severe pain in the affected area that may resemble the pain of a torn muscle
- redness around the infection site that spreads quickly
- sometimes, ulcers or blisters
If the bacteria are deep within the tissue, signs of inflammation may not be apparent in the early stages. Pain that seems out of proportion with the redness is a warning sign of necrotizing fasciitis. The skin may eventually become swollen, shiny, and hot to touch.
If the infection continues, the person may experience
- a rapid heart rate
- low blood pressure
The pain may, over time, become less as the bacteria destroy the tissues and nerves. If the infection affects vital organs, the person may experience confusion or feel delirious.
Without effective treatment, the condition can lead to shock, and it can be fatal.
Although anyone can get a necrotizing fasciitis infection, it is more likely to affect some people than others.
An underlying health condition that weakens the immune system can increase the risk of infection.
The majority of those who develop the infection have diabetes and a history of alcohol use disorder. People with liver cirrhosis are also more at risk.
In young children, this infection can be a rare complication of chickenpox.
Facial necrotizing fasciitis is extremely rare, but it can occur as a result of dental factors or issues with the sinuses or tonsils. Acne can also allow infection.
Doctors can often diagnose necrotizing fasciitis by taking a tissue sample and sending it to a lab for testing. They may also look at blood work and use imaging scans, such as CT or MRI scans, to inspect the damaged area.
The infection can be difficult to detect in the early stages. If necrotizing fasciitis starts deep under the skin, the person may not receive an accurate diagnosis for some time.
If the doctor does suspect necrotizing fasciitis, they will give the person intravenous antibiotic therapy immediately. The person will stay in the intensive care unit (ICU) during treatment.
Necrotizing fasciitis spreads rapidly and can cause extensive tissue death, so prompt treatment is crucial. Early detection minimizes the need for the surgical removal of skin and soft tissue, and it reduces the risk of toxic shock.
Sometimes, emergency surgery may be necessary to remove infected tissue. This surgery can stop the infection from spreading. In advanced cases, the person may need limb amputation surgery.
When doctors are confident that they have treated the infection, the recovery process involves extended physical therapy and long-term psychological and emotional healing.
The healthcare team will help care for the wound. People with a large open wound may need skin grafting or reconstruction surgery. Hyperbaric oxygen treatment can be a beneficial supplementary therapy for these individuals.
Experts have linked certain streptococcal strains to a poor outlook. Other factors that affect a person’s outlook and recovery time include:
- older age
- uncontrolled diabetes
- a suppressed immune system
- delayed surgery
The infection mostly occurs in people with wounds following surgery or injury. People can prevent skin infections through proper wound care, which is essential no matter how minor the wound.
Although necrotizing fasciitis is rare, people should see a doctor immediately if they experience early symptoms of wound infection after injury or surgery. These include:
- redness, warmth, or swelling in the skin that spreads quickly
- severe pain
Proper hygiene can help prevent skin infections. Good practices to adopt include:
- cleaning all wounds that break the skin with soap and water
- covering open wounds with clean, dry bandages after cleaning them
- washing the hands often with soap and water, or using alcohol-based gel when washing is not possible
- avoiding spending time in hot tubs, swimming pools, lakes, or rivers with an open wound or skin infection
Necrotizing fasciitis is not usually contagious. Most cases occur randomly, and it is rare that someone catches it from another person.
In the U.S., the Centers for Disease Control and Prevention (CDC) use a system called Active Bacterial Core surveillance to monitor cases of necrotizing fasciitis due to group A Streptococcus. The data show that the incidence does not seem to be increasing.
Necrotizing fasciitis is a rare but serious bacterial infection with a high fatality rate. It typically occurs after a person sustains a wound through surgery or injury.
Early diagnosis and treatment greatly improve a person’s outlook. Therefore, anyone who has symptoms of necrotizing fasciitis should see a doctor straight away.