Necrotizing fasciitis

Necrotizing fasciitis is a serious infection of the skin, the tissue just beneath the skin (subcutaneous tissue), and the tissue that covers internal organs (fascia).

Cause

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.

Transmission

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 system may 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.

The bacteria most commonly enter the body through a break in the skin, including:

• Cuts and scrapes
• Burns
• Insect bites
• Puncture wounds (including those due to intravenous or IV drug use)
• Surgical wounds
• However, people can also get necrotizing fasciitis after an injury that does not break the skin (blunt trauma).

Symptoms

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

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

Diagnosis

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:

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

Treatment

Accurate and prompt diagnosis, treatment with intravenous (IV) antibiotics, and surgery to remove dead tissue are 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.

Prognosis

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.

Images

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  The very first symptom of NF. The center is clearly getting darker red (purple).

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  Early symptoms of necrotizing fasciitis. The darker red center is going black.

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  Necrotizing fasciitis type III caused by vibrio vulnificus.

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