What Is Necrotizing Fasciitis?

Necrotizing fasciitis (NF), commonly referred to as the “flesh-eating bacteria,” is a bacterial organism that quickly invades and destroys skin tissue. The most common cause of necrotizing fasciitis is group A Streptococcus.¹ Necrotizing means “death of tissue," fasciitis refers to the involved tissue, fascia. Fascia is the tissue beneath the skin and surrounds other structures, such as muscles, fat, blood vessels, and nerves. As the infection travels via the fascia, it is fast spreading.² At first, the outlying skin is unaffected, although the patient may complain of tenderness, swelling, or redness. When the skin begins to break down, it is often necrotic, requiring immediate surgical intervention. Necrotizing fasciitis is not contagious.

How Do Patients Develop Necrotizing Fasciitis?

The most common way for the bacteria that cause necrotizing fasciitis to enter the body is through a break in the skin, such as the following³:

• Cut or scrape 
• Puncture wound
• Surgical wound

Occasionally, necrotizing fasciitis can occur as a result of blunt force trauma without a break in the skin, although this entry route is less common.¹ Any comorbidities and related treatments that weaken the immune system can make one more susceptible to necrotizing fasciitis, such as diabetes, cancer, advanced age, and chronic steroid therapy. Diabetes is the most common comorbidity among patients with NF.²

What Are the Signs and Symptoms of Necrotizing Fasciitis?

NF is not easily diagnosed. Initially, it may be diagnosed as cellulitis or other inflammatory issues in the skin. Early necrotizing fasciitis presents as a red, swollen, warm area that spreads very quickly with severe pain. Disproportionate, severe pain that is beyond the degree of injury is a classic symptom.³

Certain medications, such as anti-inflammatory drugs, may obscure symptoms further by decreasing pain and fever. In addition, patients with diabetes-related neuropathy may not exhibit the pain characteristic of NF.² Some patients may even appear almost asymptomatic at initial presentation, depending on the location of initial infection and amount of redness. In some instances, patients will not show visible signs until vital soft tissues and even muscles are damaged and necrotized extensively. Skin lesions are typically a sign of NF reaching an advanced stage.³

The severity and symptoms of NF can be derived from several factors, including the type and amount of bacterial organisms present. Certain organisms may³:

• Produce endotoxins, which may present symptoms of sepsis, like hemodynamic instability and lactic acidosis, or of toxic shock syndrome
• Produce gas, which may result in subcutaneous crepitus, detectable by palpation of the affected area(s)

Because necrotizing fasciitis is systemic, the patient will usually develop a fever. The skin may present with ulcerations or blisters that quickly evolve into dark necrotic tissue. To differentiate NF from other soft tissue infections, experts in 2004 developed the Laboratory Risk Indicator for Necrotizing Infection (LRINEC) score, which evaluates 6 features: C-reactive protein, hemoglobin, sodium, creatinine, glucose levels, and white blood cell count.² To diagnose necrotizing fasciitis, wound care professionals should obtain a thorough history of the symptoms, blood work, imaging, tissue biopsy, and cultures. Severe complications of necrotizing fasciitis can include¹:

• Sepsis
• Shock
• Amputations
• Organ failure
• Death

The patient may also have life-long issues such as scarring or loss of muscle.

How to Treat Necrotizing Fasciitis

Necrotizing fasciitis requires hospitalization as it is very serious. Early recognition and treatment are essential for best long-term outcomes. IV antibiotics are administered to fight the infection, and surgical debridement may be required to remove the advancing necrotic tissue. In very advanced cases, amputation may be warranted. The patient will also need nutritional support, adequate fluids via IV, and pain management. Adjunctive treatments may be utilized alongside surgical interventions, and broad-spectrum antibiotics, like hyperbaric oxygen and IV immunoglobulins.³

How to Prevent Necrotizing Fasciitis

Although there has been a public scare regarding necrotizing fasciitis, it is quite rare.¹ According to the CDC, necrotizing fasciitis is fatal in 1 out of 5 cases.¹ For this reason, clinicians must educate patients about prevention and symptoms of NF. Good handwashing, especially when caring for wounds, although simple, is essential. All wounds should receive standard of care. Contrary to popular belief, wounds do not "need to breathe" and should always be covered to prevent bacteria and other debris from entering the site.

Wound patients should avoid water sources such as pools, open bodies of water, hot tubs, etc. Patients must not soak wounds in any solution without direction from a wound care professional. Any wound that shows the symptoms listed above warrants emergent care. There is no vaccine to prevent necrotizing fasciitis.

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