Necrotizing fasciitis, caused by Staphylococcus aureus, spreads swiftly and can lead to death. A timely diagnosis of necrotizing fasciitis can save the patient.

Necrotizing Fasciitis

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Ismail Munir

Overview

Necrotizing fasciitis (also known as flesh-eating disease, streptococcal gangrene, and suppurative fasciitis) is a rare bacterial infection that involves the skin and the layers of tissue beneath it<a href="#accordion">[1]</a>.&nbsp;

The infection spreads rapidly across the body and often results in death. At least 1 in 5 individuals with necrotizing fasciitis die from the infection<a href="#accordion">[2]</a>. This is why prompt treatment with antibiotic therapy is commenced as soon as it&rsquo;s diagnosed. It may require surgery as well to stop the infection from progressing<a href="#accordion">[2]</a>.

Many types of bacteria can cause flesh-eating disease, but public health experts believe that group A streptococcus is the most common offending agent<a href="#accordion">[2]</a>. Additionally, necrotizing fasciitis caused by group A strep is characterized as the fastest spreading infection; necrotizing fasciitis caused by other bacteria neither progresses at this speed nor is it as dangerous<a href="#accordion">[3]</a>.

Flesh-eating disease does not commonly affect healthy individuals; however, it is possible for the bacteria to enter through a minor cut or break in the skin. It is imperative to know the symptoms of this deadly infection so that it can be immediately identified and medical help can be sought before it becomes too late<a href="#accordion">[3]</a>.

<div>&nbsp;</div>

In the U.S, 600-700 cases of necrotizing fasciitis are reported each year. Of these 25-30% cases result in death. The infection rarely affects children<a href="#accordion">[1]</a>.

In 2002, a study conducted at the Aga Khan University Hospital, Karachi, Pakistan investigated 5 cases of necrotizing fasciitis of the head and neck region. It revealed that dental foci of infection were a major cause and that imaging technique can be used to diagnose and identify the extent of necrotizing fasciitis. 4 out of 5 patients survived due to rigorous treatment<a href="#accordion">[4]</a>.

<div>&nbsp;</div>

The following are the main types of necrotizing fasciitis<a href="#accordion">[5]</a>:

&nbsp;

<ul>
	<li>
	<h5>Type I&nbsp;</h5>
	</li>
</ul>

This is the polymicrobial type of necrotizing fasciitis, which means multiple bacteria are involved in causing the infection. It is usually seen in older adults and people having diabetes or other predisposing conditions.&nbsp;

&nbsp;

<ul>
	<li>
	<h5>Type II&nbsp;</h5>
	</li>
</ul>

This type is commonly known as flesh-eating disease and is caused by group A streptococcus. It affects individuals of all age groups, including healthy individuals.

&nbsp;

<ul>
	<li>
	<h5>Type III</h5>
	</li>
</ul>

This type of necrotizing fasciitis is known as gas gangrene and is caused by Clostridium perfringens. It happens after a surgical procedure or after a major injury to the skin that causes gas to collect under the skin. It can be identified by crepitus, a crackling sound in a joint. Intravenous drug abusers can also be subjected to this type of infection.&nbsp;

&nbsp;

<ul>
	<li>
	<h5>Other Organisms&nbsp;</h5>
	</li>
</ul>

Marine organisms can also cause necrotizing fasciitis. These infections are quite serious and need prompt treatment as they can be fatal within 48 hours.&nbsp;

Fungal infection can also complicate skin wounds in individuals who are immunocompromised and cause necrotizing fasciitis.

Necrotizing fasciitis that affects the genital and perineal region is known as Fournier gangrene and it has a mortality rate of 15-50%.&nbsp;

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Signs And Symptoms

Initially, the signs and symptoms of necrotizing fasciitis may not seem significant enough to prompt concern. The skin on the affected site may become hot and tender and symptoms of flu may develop<a href="#accordion">[3]</a>.

Some people can develop a red, painful bump that is initially small, but it grows and becomes excruciatingly painful with time<a href="#accordion">[3]</a>. Pus or exudate can ooze from the affected area and the infected region may change its color as the infection progresses.&nbsp;

&nbsp;

Necrotizing fasciitis presents itself within the initial 24 hours of infection. The early symptoms of this infection include<a href="#accordion">[1]</a>:&nbsp;

<ul>
	<li>Inflammation of the skin</li>
	<li>Severe pain in the affected region of the skin (e.g., abrasions and cuts)</li>
	<li>Pain that is disproportionate compared to the appearance of the infected area</li>
	<li>Warmth and redness around the infected site&nbsp;</li>
	<li>Flu-like symptoms, such as fever, nausea, diarrhea, malaise, and dizziness</li>
	<li>Increased thirst due to dehydration</li>
</ul>

&nbsp;

Symptoms advance with time and the following signs and symptoms present by the 3rd or 4th day of infection<a href="#accordion">[1]</a>:

<ul>
	<li>Swelling of the affected area accompanied by a purplish rash&nbsp;</li>
	<li>Dark purple-colored and large blisters that contain foul-smelling liquid&nbsp;</li>
	<li>Gangrene or the death of the involved tissue ensues; it presents as discolored and flakey skin that peels off easily</li>
</ul>

&nbsp;

If treatment is not initiated, life-threatening symptoms present within 4-5 days of the infection. These include<a href="#accordion">[1]</a>:&nbsp;

<ul>
	<li>A rapid and severe reduction in the blood pressure&nbsp;</li>
	<li>Toxic shock&nbsp;</li>
	<li>Unconsciousness</li>
</ul>

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Causes

The most common cause of necrotizing fasciitis is the bacteria that is also responsible for causing sore throat &ndash; group A streptococcus<a href="#accordion">[1]</a>. However, there are other bacteria, such as staphylococcus, which also cause this flesh-eating disease. Moreover, Vibrio vulnificus, which is a bacterium that lives in water, can also cause flesh-eating disease<a href="#accordion">[2]</a>.&nbsp;

Necrotizing fasciitis develops when these bacteria enter through a break in the skin and infect superficial fascia, a connective tissue layer beneath the skin.&nbsp;

&nbsp;

The bacteria that cause necrotizing fasciitis can enter the host body through<a href="#accordion">[2]</a>:&nbsp;

<ul>
	<li>Burns</li>
	<li>Surgical wounds&nbsp;</li>
	<li>Puncture wounds due to IV drug use</li>
	<li>Small cuts&nbsp;</li>
	<li>Abrasions&nbsp;</li>
	<li>Insect bites</li>
</ul>

&nbsp;

Once inside, the infection spreads rapidly and destroys the skin, fat, and muscle tissue<a href="#accordion">[1]</a>.

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Diagnosis

Diagnosing necrotizing fasciitis is a complicated process yet crucial for the survival of the individuals. Early diagnosis will enable prompt treatment to prevent the infection from spreading<a href="#accordion">[1]</a>.

&nbsp;

Besides a proper history and a physical examination, the doctor will run the following test for urgent diagnosis of necrotizing fasciitis<a href="#accordion">[1]</a>:&nbsp;

&nbsp;

<ul>
	<li>Blood Tests: To check for increased white blood cells which indicate infections, such as necrotizing fasciitis.</li>
</ul>

&nbsp;

<ul>
	<li>Biopsy Of The Tissue: Surgery is done to remove a part of the affected area. The sample of tissue collected is then sent to the laboratory for evaluation of the type of bacteria that is causing the disease. However, antibiotics should be started immediately rather than waiting until the biopsy results come back.&nbsp;</li>
</ul>

&nbsp;

<ul>
	<li>CT Scan: It helps the doctor visualize where the pus and fluid are collected in the body. The presence of gas bubbles under the skin is diagnostic of necrotizing fasciitis.</li>
</ul>

<div>&nbsp;</div>

Treatment

Since necrotizing fasciitis can progress quickly and be fatal, the affected individuals should be taken to the hospital and provided with medical care as soon as possible.&nbsp;

&nbsp;

Necrotizing fasciitis treatment include the following<a href="#accordion">[1][6]</a>:&nbsp;

<ul>
	<li>Intravenous (IV) antibiotics to control the spread of infection</li>
	<li>Surgery to remove the dead tissue</li>
	<li>Amputation of the affected limb in certain cases&nbsp;</li>
	<li>High-pressure oxygen therapy</li>
	<li>Blood transfusions</li>
	<li>Breathing aids</li>
	<li>Intravenous immunoglobulin to provide support to the body to fight the infection</li>
</ul>

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Necrotizing fasciitis can lead to many complications, such as<a href="#accordion">[2]</a>:

<ul>
	<li>Shock&nbsp;</li>
	<li>Sepsis&nbsp;&nbsp;</li>
	<li>Multiple organ failure&nbsp;</li>
	<li>Loss of limbs&nbsp;</li>
	<li>Severe scarring&nbsp;</li>
	<li>Death&nbsp;&nbsp;</li>
</ul>

<div>&nbsp;</div>

Individuals who have a weak immune system are predisposed to develop flesh-eating disease. Following conditions may increase the risk of developing necrotizing fasciitis<a href="#accordion">[1]</a>:

<ul>
	<li>Cancer</li>
	<li><a href="https://www.merisehat.pk/disease/cirrohsis" target="_blank">Cirrhosis&nbsp;</a></li>
	<li>Chicken pox during childhood</li>
	<li>Alcohol abuse</li>
	<li><a href="https://www.merisehat.pk/disease/diabetes-type-1-and-2" target="_blank">Diabetes&nbsp;</a></li>
	<li>Chronic kidney disease&nbsp;</li>
	<li>Heart disease involving heart valves&nbsp;</li>
	<li>Lung diseases, such as <a href="https://www.merisehat.pk/disease/tuberculosis" target="_blank">tuberculosis&nbsp;</a></li>
	<li>Use of steroids&nbsp;</li>
	<li>Use of IV drugs</li>
	<li>Peripheral vascular disease&nbsp;</li>
</ul>

<div>&nbsp;</div>

One of the best ways to prevent necrotizing fasciitis from developing is to take good care of wounds or any break in the skin because any breach in the normal skin lining usually results in this infection.&nbsp;

&nbsp;

Following steps should be taken to prevent group A strep from causing flesh-eating disease<a href="#accordion">[2]</a>:

&nbsp;

<ul>
	<li>Use soap and water to properly clean small cuts or abrasions on the skin.&nbsp;</li>
	<li>Cover the open wounds with a bandage after cleaning.</li>
	<li>Consult a doctor immediately if the wound appears serious or deep.&nbsp;</li>
	<li>Use alcohol-based swabs and sanitizer if soap and water is not available to clean the skin.&nbsp;</li>
	<li>Take care of any fungal infection, such as athlete&#39;s foot.&nbsp;</li>
	<li>Avoid walking barefoot if there&rsquo;s any injury or cut on the skin.&nbsp;</li>
	<li>Avoid using hot tubs, swimming pools, and natural water bodies (e.g., rivers, ponds, and lakes) if there&rsquo;s any skin infection or open wound.</li>
</ul>

&nbsp;

Necrotizing fasciitis is a life-threatening soft tissue infection that requires immediate diagnosis and treatment, which includes surgical debridement. For confirmation of the diagnosis, imaging modalities like CT scan are often used. However, they can the delay the commencement of treatment<a href="#accordion">[7]</a>.&nbsp;

Point-of-care ultrasound (POCUS) is used in the emergency department to diagnose soft tissue infections. A study was conducted to evaluate the effectiveness of POCUS in diagnosing necrotizing fasciitis patients that present in the emergency department. The patients received both a CT scan and POCUS to compare the findings. The results indicated that POCUS has high sensitivity and specificity for diagnosing necrotizing fasciitis<a href="#accordion">[7]</a>.

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Key Points

<ul>
	<li>Necrotizing fasciitis is a fatal bacterial infection of the soft tissue.</li>
	<li>It is the most rapidly spreading infection.</li>
	<li>Also known as flesh-eating disease, this infection is most commonly caused by group A strep.&nbsp;</li>
	<li>Intravenous antibiotics and surgery are the first-line treatments.</li>
	<li>The infection presents as warm and red swelling over the affected area that is excruciatingly painful.&nbsp;</li>
	<li>Immunocompromised individuals or those having other medical conditions such as <a href="https://www.merisehat.pk/disease/diabetes-gestational" target="_blank">diabetes </a>or <a href="https://www.merisehat.pk/disease/cirrohsis" target="_blank">cirrhosis </a>are at a greater risk of developing the disease.</li>
	<li>Wound care is crucial in order to prevent infection from developing.&nbsp;</li>
</ul>

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[1] McMillen M. Necrotizing Fasciitis (Flesh-Eating Bacteria): Causes, Symptoms, and Treatment. WebMD.

[2] Necrotizing fasciitis: All you need to know. Centers for Disease Control and Prevention.

[3] Holm G. Necrotizing Fasciitis: Causes, Symptoms, and Treatment. Healthline.

[4] Ikram M, Saeed O, Ali SS, Salahuddin I. Necrotizing fasciitis of head & neck: the Pakistani experience. Asian J Surg. 2002;25(1):13-17.

[5] Ngan V. Necrotising fasciitis | DermNet.

[6] Necrotising fasciitis. NHS.

[7] Lahham S, Shniter I, Desai M, et al. Point of Care Ultrasound in the Diagnosis of Necrotizing Fasciitis. Am J Emerg Med. 2022;51:397-400. doi:10.1016/j.ajem.2021.10.033