Necrotizing Fasciitis

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NF site of infection on upper thigh http://emedicine.medscape.com/article/784690-overview
Necrotizing Fasciitis (NF) is a flesh-eating disorder that causes an infection to the deeper layers of the skin. NF is caused by the hemolytic streptococcus bacteria which is a progressive, rapidly spreading, inflammatory infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues [3]. This disease may also lead to toxic shock syndrome which is another form of the Streptococcus bacterial infection. If not treated immediately, it can result in severe morbidity or even death. People with chronic diseases such as diabetes, kidney disease, or cancer have a higher risk of developing the infection when the immune system is weakened [7].

History

There have been many claims to when NF was first discovered. The earliest discovery of the disease was said to be made in the 5th century B.C by Hippocrates when he described it as a complication of erysipelas [4]. Erysipelas is another type of bacterial infection to the skin caused by a group A Streptococcus bacteria, with similar symptoms such as inflammation and redness. NF was then found in the United States in 1871 during the Civil War. It is most often credited to a confederate army surgeon, Joseph Jones after he observed many cases in military hospitals [5]. During this time it was thought to be Fournier’s gangrene due to its description as a type of necrotizing bacterial infection to soft tissue of the perineum. Later Fournier’s gangrene was restricted specifically to the genital area, therefore concluding that Jones’s interpretation could not be correct. By the 1920’s it was then characterized as necrotizing fasciitis after U.S. surgeon Franklin L. Meleney asserted that 20 patients he examined in China were afflicted with necrotizing fasciitis caused by hemolytic streptococcus [6]. The most modern term “flesh eating bacteria” was given to the disease in 1990’s by the media after their own interpretation of the disease.

Symptoms

Necrotizing Fasciitis is a bacterial infection that usually begin with a pre-existing wound. Cuts on skin, puncture wounds, surgical incisions, and insect bites are all sites of initial infection. Unlike normal wounds, this one does not heal and turns red with the presence of a swollen area [1]. The infected area will feel hot to the touch and will be very painful [2]. Symptoms of the infection range from flu-like symptoms, fever, chills, and an area sensitive to pain. There are different types of the infection that range from type 1 to type 3, with type 1 being the most severe.The symptoms vary for each type so diagnosis is usually based on the organism(s) found in the patient [1]. Some patients even experience the infection spreading to the blood stream, which is also a severe aspect of the infection. Gangrene, toxemia, organ failure, and death are often the result of this bacterial infection with most cases being caused by toxins produced by a single organism such as group A streptococcus [8]. Patients with symptoms will be hospitalized in an intensive care unit and immediately started on antibiotics [1]. A surgeon will be contacted to determine the severity of the infection. Patients with any symptoms should explain all symptoms to the doctor so the correct diagnosis can be determined and aggressive treatment can be given to reduce morbidity and mortality [3].

Mechanisms

NF is an invasion of rapidly progressing soft tissue infection producing necrosis at the fascia level and may also involve overlying tissue or underlying muscle tissue [4]. The infection travels along the fascia planes and later moves into deeper muscles which results in damage like myositis and myonecrosis. There are two main groups of causative organisms. Type I infections display synergistic polymicrobial qualities, and tend to occur in patients with multiple comorbidities. Type II infection is caused by Streptococcal infection or staphylococcal infection [5]. Necrotizing fasciitis starts with any type of bacteria entering an open wound on an individual. The wound can be as little as a paper cut and can even enter the body through a bruise or weakened area of the skin. It is also possible to get this through bodily fluids, so coming in close contact with people and their fluids if they have a bacterial infection can cause this disease to manifest. NF damages the subcutaneous tissues and causes a rapid destruction of fat and fascia and, weakening the immune system and disabling its ability to fight off bacterial infections.It can be caused by different kinds of bacteria and are divided into three types; type 1 polymicrobial, type 2 or group A streptococcal,and type 3 gas gangrene[6].

Treatments

When symptoms of NF are present, the individual should should go to the hospital to seek immediate treatment. The first step to treat this is to perform surgical debridement, which is removal of the infected tissue in order to prevent further spreading [2]. The patient should also be treated with antibiotics immediately to stop the spreading of the disease. A diagnosis at an early stage is crucial for the patient’s health and can make a substantial impact.It is important because doctors often fail to recognize the disease since the symptoms are similar to those of the flu. There are several ways to treat the disease, but the most common is with antibiotics and surgical removal of dead tissue [2].

Prognosis

The prognosis of NF can be severe morbidity and even death if left untreated. For the best outcome this disease should be treated as soon as possible. The disease can be cured, but can lead to a shorter lifespan. Severe morbidity is fairly common with NF which in most cases is limb loss. Gangrene has a very high rate of about 75% of patients that are diagnosed with the disease. Mortality occurs in about 25% of patients, however there is a strain called Vibrio vulnificus, which has a mortality rate as high as 50% [1]. Other complications of NF are scar formation, renal failure, and sepsis, which is a type of bacterial infection in the bloodstream. The younger the patient, the more likely their immune system will be able to fight the infection, therefore giving them a better chance to survive against the disease. The most important part of surviving this disease is early diagnosis. The disease is curable, but most patients will have some form of morbidity at least scars since it is a flesh-eating disease.

Current Research

There is not a lot of current research that is being conducted on Necrotizing Fasciitis. However, an experimental treatment is being done on patients with this disease. It is not available in most hospitals but Hyperbaric Oxygen Therapy is being used on some patients. In this procedure the patient is put into a chamber and oxygen is given under pressure. The oxygen can be used to help promote tissue recovery. The oxygen may also stop anaerobic bacterial growth. This treatment has been shown to reduce morbidity and mortality by around 10-20% [1]. This treatment should be performed along with giving the patient antibiotics and performing surgery if necessary. Today, Canadian researchers are working on new strategies to help treat this disease [7]. There was a study recently conducted with a drug called Daptomycin, which is a new antimicrobial agent to help fight infection [8]. This study uses a higher dose of the drug than previous studies because one of the organisms that is involved in NF is a form of gram positive bacteria that resembles streptococci [8]. The treatment requires a higher dosage of Daptomycin so that adequate serum concentration of the drug is achievable. The results of this study have not yet been posted.

References

[1]MedicalNet.Com (1996-2009). Retrieved November 1, 2010, from [1]

[2]The National Necrotizing Fasciitis Foundation (1998-2010). Retrieved November 1, 2010, from [2]

[3]emedicine.medscape.com. (2009, March 25). Retrieved November 1, 2010, from [3]

[4]Edelman L., Graves C., Morris S., Saffle J., , Stauffer T. (2004). Caloric Requirements in patients with Necrotizing Fasciitis. Burns, 31:55-59 [4]

[5]G H Smith, J S Huntley, G F Keenan. (2007). Necrotising myositis: a surgical emergency that may have minimal changes in the skin. Emergency Casebook, 24:1-2. [5]

[6]Medscapes continually updated clinical references, Emedicine. Retrieved November 3, 2010, from [6]

[7]Manitoba Health Public Health. (2001). Necrotizing fasciitis(“Flesh-eating Disease). Communicable Disease Control[7]

[8]University of Maryland. (2008). Daptomycin for the Treatment of Severe Necrotizing Soft-Tissue Infections. [8]

[9]Roemmele,Jacqueline A., and Batdorff Donna. (2000). Surviving teh "Flesh-Eating Bacteria":Understanding, Preventing, treating, and living with the effects of Necrotizing Fasciitis. Penguin Putman Inc. Pg 3-10.

[10]ehow.com.The History of Necrotizing Fasciitis. (1999-2010). Retrieved November 2, 2010,From [9]

[11]Feely,E.(1998).Necrotizing Fasciitis:Diagnostic Modalities.Retrieved November 2, 2010, From [10]