Necrotizing Fasciitis

What is Necrotizing Fasciitis

Necrotizing fasciitis is a severe bacterial infection of the skin and the tissues underneath the skin.

The bacteria that cause this infection have been called “flesh-eating bacteria” because the infection can quickly kill flesh around the infection.

Necrotizing fasciitis is an aggressive, rapidly progressive, and frequently fatal infection involving the fascial layers of the body, often by polymicrobial organisms, and is a surgical emergency. Its diagnosis, although primarily clinical, also rests on the identification of soft tissue emphysema (i.e., gas in the soft tissues).

Large quantities of gas can be easily diagnosed via radiography, while smaller amounts may require the use of CT. Other suggestive imaging features include fascial plane thickening, edema, or enhancement, as well as edema, phlegmon, or abscess formation in subjacent muscles.

Whether radiography or CT is used, the imaging test and its interpretation are rapidly provided, and if the clinical and imaging findings support this diagnosis, then the patient is taken to the operating room for debridement and is also treated with antimicrobial agents.

Slower imaging modalities such as MRI and US are less often utilized when this diagnosis is suspected.

Necrotizing fasciitis is very rare in people who have a normal disease-fighting (immune) system.

It most often affects people who have a weak immune system. This condition is a medical emergency that must be treated quickly. Untreated necrotizing fasciitis can be life-threatening.

What are the causes?

This infection is caused by bacteria. There may be one type of bacteria or a combination of bacteria. Streptococcus and staphylococcus are common types of bacteria that can cause this infection. These bacteria are often found on the skin.

In most cases, bacteria enter the tissue under the skin through a:

• Cut.
• Scrape.
• Surgical incision.
• Insect bite.
• Needle puncture.

Once inside the body, the infection spreads along tissue that covers the muscles (fascia). The bacteria produce poisons (toxins) that kill tissues as the infection spreads. This reduces the blood supply to the surrounding tissues and causes more cell death. This makes it hard for the immune system to fight the infection.

What increases the risk?

You may have a higher risk of this condition if you:

• Have a weak immune system.
• Are of advanced age.
• Have another medical condition, such as:
  • Diabetes.
  • Cancer.
  • Kidney disease.
  • Liver disease.
  • A blood vessel disease.
  • HIV (human immunodeficiency virus) or AIDS (acquired immunodeficiency syndrome).
  • Lymphedema.
• Have recently had surgery.
• Are obese.
• Abuse drugs or alcohol.

What are the symptoms?

Symptoms start quickly. Severe pain is the main symptom. Other early signs and symptoms may include:

• Redness and warmth.
• Flu-like symptoms.
• Skin color changing from red to purple, and then to dark spots.
• Swelling that makes the skin feel hard (hard swelling).
• Crackling noise when pressing on the skin (crepitus).
• High fever and chills.
• Vomiting.

As the condition gets worse, these signs and symptoms may develop:

• Blisters, ulcers, or splitting of the skin.
• Drainage of pus and fluid.
• Rapid breathing.
• Sudden decrease in pain.
• Confusion.
• Loss of consciousness.

How is this diagnosed?

It is important to diagnose this condition as soon as possible. This condition may be diagnosed based on:

• Surgery to open the infected area and check for tissue death (surgical exploration). This is often the most important part of diagnosis. During surgical exploration, samples of tissue may be taken, and dead tissue may be removed.
• Your symptoms.
• Your medical history.
• A physical exam.
• Blood tests.
• Imaging tests, such as:
  • X-rays.
  • Ultrasound.
  • CT scan.
  • MRI.
• Taking fluid samples of drainage from the skin or underneath the skin to test for the type of bacteria that may be causing the infection (cultures).

How is this treated?

This condition is treated as an emergency at the hospital. Treatment may include:

• Fluids and antibiotic medicines given through a vein.
• Medicines to support blood pressure.
• Surgery to open the skin and remove dead or dying tissue. This may need to be repeated until your condition improves. Surgical incisions may be packed with gauze and left open until the infection is controlled. After the infection has been controlled, plastic or reconstructive surgery may be done to close the incisions with skin from another area of your body (graft).

Follow these instructions at home:

• Take your antibiotic medicine as told by your health care provider. Do not stop taking the antibiotic even if you start to feel better or your condition improves.
• Do not use any tobacco products, such as cigarettes, chewing tobacco, and e-cigarettes. If you need help quitting, ask your health care provider.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

• Wash your hands frequently with soap and warm water. If soap and water are not available, use hand sanitizer.
• Wash broken skin with soap and water and cover it with a clean, dry bandage until healed.
• Use germ-killing cream or ointment on cuts and sores.
• Do not go in hot tubs, swimming pools, lakes, or ponds if you have an open cut.

Contact a health care provider if:

• You have a fever or chills.
• You have a wound that develops signs of infection, such as:
  • Redness, swelling, or pain.
  • Warmth.
  • A bad smell.
  • Fluid, blood, or pus.

Get help right away if:

• You have severe pain.
• Your skin changes color.
• You develop hard swelling.
• You have a wound that splits open.