The flesh-eating disease invades the body, uses the bloodstream to travel, but then blocks the flow of blood and destroys tissue. It causes severe pain and fever. Blood clots and blisters form. Areas of the body start to swell, with skin changing from one color to another. Many victims even go into shock.
Definition
The medical term for flesh-eating disease is necrotizing fasciitis. The disease is necrotizing because it causes the death of tissues. Fasciitis means the inflammation of the fascia, the layers beneath the skin. As explained by Keith Moore, an anatomy and cell biology professor, in "Essential Clinical Anatomy," the upper layer of fascia, called the superficial fascia, contains fat, connective tissue, nerves, blood, sweat glands and lymphatic vessels. Below the superficial fascia is the deep fascia, which surrounds muscles.
Risk Factors
Mucous membranes line the intestinal, genital and urinary structures of the body. Hemorrhoids, diverticula, an anal fissure, a stab in the abdomen, a tear in the urethra, malignancy, surgery and diabetes can all interfere with that lining or barrier. Any of these conditions can provide an opening in a mucous membrane to let in bacteria that cause necrotizing fasciitis, according to Dr. Dennis Stevens, an infectious diseases specialist, in "Harrison's Principles of Internal Medicine." Diverticula are little pouches that stick outward from the intestines. An anal fissure is a tear in the mucous membrane at the anus.
Development of Disease
The Streptococcus pyogenes bacteria can enter the skin where there is a muscle strain, skin infection or bruise. Then they get into the bloodstream and use the blood to travel to distant sites. They can also get to the deep fascia if you have a deep cut. Dr. A. Damian Dhar of the Atlanta Dermatology, Vein and Research Center writes about the development of this disease on the Merck Manuals website. The bacteria interfere with the flow of blood in the fascia, leading to necrosis (tissue death). Other bacteria can now grow and multiply in that area. Some of them produce nitrogen and hydrogen gases, and the gases accumulate in the tissue.
Symptoms
At first, people will have severe pain and fever, according to Stevens in "Harrison's Principles of Internal Medicine." Then the infected area will swell and become very tender. The skin changes and looks dark red. Blisters will develop that are filled with purple or blue fluid. The skin now becomes purplish, blue or black. Clots form in the blood vessels, and the tissue changes again to look brown and gray. The infection spreads along the fascia. People may go into shock and have low blood pressure, rapid heartbeat and mental confusion.
Evaluation
As explained by Dhar in the Merck Manuals, physicians will make the diagnosis initially by getting a medical history and doing a physical exam. A CBC, or complete blood count, is done to see if the white blood cell count is high. These cells fight infection. An X-ray of the infected area is taken to see if the tissue contains any gases. A blood culture will determine if any bacteria are in the bloodstream and what kind. The lab will also do a Gram stain and culture of some of the infected tissue to identify the bacteria in the infected area.
Treatment
The treatment of necrotizing fasciitis depends on the extent of the damaged tissue. If it is caught early, surgery is the main treatment, but two or more antibiotics are also used. If it is not caught early, surgery and antibiotics are still the treatment, but a second surgery may be needed in one to two days. If the damage is severe, amputation may need to be done.
Prognosis
Necrotizing fasciitis is not contagious. People do not necessarily contract it by being in contact with someone who has this disease. There must be an infection, cut or bruise that the bacteria can use to enter the bloodstream. Even then, good hygiene habits should prevent an infection. But for those with this disease, Dr. Dhar cites the mortality rate at approximately 30 percent.
References
- "Essential Clinical Anatomy"; Keith Moore, Anne Agur; 1995
- "Harrison's Principles of Internal Medicine"; Dr. Anthony Fauci, Dr. Dennis Kasper, Dr. Dan Longo et al; 2008
- Merck Manuals: Necrotizing Subcutaneous Infection (Necrotizing Fasciitis)
