Necrotizing Fasciitis: Everything You Need to Know

Necrotizing fasciitis is a very dangerous condition Once this infection sets in, the risk of death is high if action is not taken quickly and aggressively. Learn more here.
Necrotizing Fasciitis: Everything You Need to Know

Last update: 12 September, 2021

What we know as necrotizing fasciitis has other names as well, such as Fournier’s gangrene or gas gangrene. It’s a very dangerous condition that seriously endangers the health of those who suffer from it.

This is an infection of the soft tissues that kills skin cells, the subcutaneous cellular layer, and even the muscles. The bacteria that promote this cell death move at high speed and make initial diagnosis difficult.

The microorganisms enter the deeper layers of the skin through a wound or opening that may be minimal. However, once inside, they multiply in various ways. Some produce toxins, and others mobilize the immune system.

Among patients with necrotizing fasciitis who undergo surgery, mortality reaches more than 20%. In some strains, there have been reports of mortalities of as high as 40%.

It doesn’t usually appear in children, so experts consider it a rarity in pediatrics. On the contrary, risk groups are adults with chronic diseases such as diabetes and cancer.

The symptoms of necrotizing fasciitis

Necrotizing fasciitis evolves silently at first, which can delay diagnosis and complicate the course and prognosis. Early symptoms don’t tend to guide as to what’s going on.

Patients tend to suffer from a fever that they or their doctors may attribute to other causes upon examination. The pain in the area where the bacteria entered is very powerful, but its onset isn’t immediate. The painful sign becomes evident when cell death has advanced.

The nerves in that area become inflamed and even infarct. Thrombosis of the small vessels surrounding the necrotizing fasciitis infection has been present in autopsies of deceased patients.

Sepsis occurs when bacteria or their toxins reach the bloodstream and spread throughout the body. Once the pathologic course progresses to sepsis, the symptoms will be those of shock, including the following:

  • Fainting
  • Loss of consciousness
  • Increased heart rate
  • Arterial hypotension

The skin area with necrotizing fasciitis also progresses to more complex lesions. Some patients have hematomas and others blisters. A classic sign is crepitus, which is the sound that occurs when a doctor palpates the region due to the gas that bacteria deposit under the dermal tissue.

A hand with gauze wrapped around a bleeding wound on the palm.
A skin wound can be the gateway to necrotizing fasciitis.

Continue reading: Types of Skin Rash and Their Causes

The difficulty of diagnosis

When doctors can detect necrotizing fasciitis, the prognosis improves. However, as we’ve already mentioned, this is difficult at the beginning. During the first 5 days of the disease, the symptoms are non-specific and diagnosis is complicated.

In the laboratory, there are no precise indicators either. Inflammation parameters such as C-reactive protein and white blood cells increase. Experts have developed a scale–LRINEC–, which scores biochemical values to improve detection of possible ongoing necrotizing fasciitis.

Once suspicion has been established, the physician orders a blood culture. Through this test, bacteria that could be colonizing the patient’s blood are grown to find out if the patient is in the process of sepsis or not.

Imaging studies don’t provide much help in diagnosis. Perhaps they do with the evolution, once treatment has begun, but neither computed tomography nor ultrasound are accurate. Both complementary methods are non-specific and depend on the operator’s expertise.

Bacteria in the bloodstream.
Bacteria can pass into the bloodstream from the skin, leading to sepsis.

Find out more: The Importance of the Skin Microbiome

Treating necrotizing fasciitis

This disease progresses quickly and the healthcare team must move quickly and aggressively to improve the chances of patient survival. Antibiotics and surgery are used to treat necrotizing fasciitis, as well as life support if shock is present.

Antibiotics target the bacteria behind this severe skin infection. Broad-spectrum drugs are prescribed in combination to cover several microorganisms at once.

The surgical approach is debridement, i.e. opening the infected area to allow oxygen to enter and kill the anaerobic bacteria that live without it. In the long term, further plastic and reconstructive surgery will be necessary to close the skin.

If there’s sepsis shock, the patient will be admitted to intensive care and will receive the protocols of this extreme case. In the event of respiratory failure, the patient will need to use a respirator. If cardiac arrest occurs, doctors will administer medication.

Necrotizing fasciitis isn’t just a skin disease

Overall, it’s important to remember that necrotizing fasciitis is neither simple cellulitis nor passing dermatitis. Even with timely treatment, this infection can be deadly.

If you have a skin lesion that doesn’t heal or doesn’t evolve as it should, you should consult a doctor, especially if it’s accompanied by fever and pain that you can’t relieve.

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  • Navqi G, Malik S, Jan W. Necrotizing fasciitis of the lower extremity: a case report and current concept of diagnosis and management. Scand J Trauma Resusc Emerg Med 2009;17:28.
  • Ferrer Lozano, Yovanny, and Yanett Morejón Trofimova. “Escala LRINEC en la Fascitis necrosante.¿ Una herramienta diagnóstica útil?.” Revista Habanera de Ciencias Médicas 17.2 (2018): 236-243.
  • Sultan, Helen Yasmin, Adrian A. Boyle, and Nicholas Sheppard. “Necrotising fasciitis.” Bmj 345 (2012).
  • Ferrer Lozano, Yovanny, and Yanett Morejón Trofimova. “Fascitis necrosante. Actualización del tema.” MediSur 16.6 (2018): 920-929.