Necrotizing fasciitis

Necrotizing fasciitis
Specialty	Infectious diseases

Necrotizing fasciitis (NF), commonly known as flesh-eating disease or flesh-eating bacteria, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue. Type I describes a polymicrobial infection, whereas Type II describes a monomicrobial infection. Many types of bacteria can cause necrotizing fasciitis (eg. Group A streptococcus (Streptococcus pyogenes), Staphylococcus aureus, Vibrio vulnificus, Clostridium perfringens, Bacteroides fragilis).

Historically, Group A streptococcus made up most cases of Type II infections. However, since at least 2001, another serious form of monomicrobial necrotizing fasciitis has been observed with increasing frequency. In these cases, the bacterium causing it is methicillin resistant Staphylococcus aureus (MRSA), a strain of S. aureus which is resistant to methicillin, the antibiotic used in the laboratory that determines the bacterium's sensitivity to flucloxacillin or nafcillin that would be used for treatment clinically.

Symptoms

The infection begins locally, at a site of trauma, which may be severe (such as the result of surgery), minor, or even non-apparent. Patients usually complain of intense pain that may seem in excess given the external appearance of the skin. With progression of the disease, tissue becomes swollen, often within hours. Diarrhea and vomiting are also common symptoms. In the early stages, signs of inflammation may not be apparent if the bacteria are deep within the tissue. If they are not deep, signs of inflammation such as redness and swollen or hot skin show very quickly. Skin color may progress to violet and blisters may form, with subsequent necrosis (death) of the subcutaneous tissues. Patients with necrotizing fasciitis typically have a fever and appear very ill. Mortality rates have been noted as high as 73 percent if left untreated. Without surgery and medical assistance, such as antibiotics, the infection will rapidly progress, and will eventually lead to death.

Pathophysiology

“Flesh-eating bacteria” is a misnomer as the bacteria do not actually eat the tissue. They cause the destruction of skin and muscle by releasing toxins (virulence factors), which include streptococcal pyogenic exotoxins. S. pyogenes produces an exotoxin known as a superantigen. This toxin is capable of activating T-cells non-specifically, which causes the overproduction of cytokines.

Treatment

Necrotic tissue from the left leg is being surgically debrided in a patient with necrotizing fasciitis (same patient as above).

Patients are typically taken to surgery based on a high index of suspicion, determined by the patient's signs and symptoms. In necrotizing fasciitis, aggressive surgical debridement (removal of infected tissue) is always necessary to keep it from spreading and is the only treatment available. Diagnosis is confirmed by visual examination of the tissues, and by tissue samples sent for microscopic evaluation. Early medical treatment is often presumptive; thus, antibiotics should be started as soon as this condition is suspected. Initial treatment often includes a combination of intravenous antibiotics including penicillin, vancomycin and clindamycin. Cultures are taken to determine appropriate antibiotic coverage, and antibiotics may be changed when culture results are obtained. As in other maladies characterized by massive wounds or tissue destruction, hyperbaric oxygen treatment can be a valuable adjunctive therapy, but is not widely available. A recent study demonstrated excellent clinical outcomes from the use of topical negative pressure, a technology which is portable and readily available. Amputation of the affected organ(s) may be necessary. Repeat explorations usually need to be done to remove additional necrotic tissue. Typically, this leaves a large open wound which often requires skin grafting. The associated systemic inflammatory response is usually profound, and most patients will require monitoring in an intensive care unit.

Historical Victims

• King Herod the Great of Judea suffered from Fournier gangrene, (necrotizing fasciitis of the groin and genitalia) at the time of his death.

Notable Recent Victims

• David Walton, a leading economist in the UK and a member of the Bank of England’s Monetary Policy Committee which is responsible for setting interest rates, died of the disease within 24 hours of diagnosis on June 21, 2006.
• Lucien Bouchard, former premier of Québec, Canada, who became infected in 1994 while leader of the federal official opposition Bloc Québécois party. He lost a leg to the illness.
• Eric Allin Cornell, winner of the 2001 Nobel Prize in Physics, lost his left arm and shoulder to the disease in 2004.
• Melvin Franklin, bass singer for The Temptations. Though Franklin’s condition was diagnosed early enough to prevent complete amputation of his arm, he died from other health complications soon afterward in 1995.
• Jan Peter Balkenende, Prime Minister of the Netherlands since 2002, was infected in 2004. He was in the hospital for several weeks, but recovered fully.
• Alan Coren, British writer and satirist, announced in his Christmas 2006 column for The Times that his long absence as a columnist had been due to contracting the disease while on holiday in France.
• Alexandru Marin, an experimental particle physicist, professor at MIT, Boston University and Harvard University, and researcher at CERN and JINR, died from the disease in 2005.
• R. W. Johnson, South African journalist and historian, contracted the disease in March 2009 after injuring his foot while swimming. His leg was amputated above the knee.
• Jeff Moorad, former agent and partial owner of the San Diego Padres and Arizona Diamondbacks, contracted the disease in 1997. He had seven surgeries in a little more than a week, but later recovered fully.

Examples in Popular Media

• Dr. Atul Gawande, in his book Complications: A Surgeon's Notes on an Imperfect Science correctly diagnoses NF in the leg of a patient named "Eleanor" and recounts his thought process behind making that diagnosis as a subject of discussion.
• TV show House MD shows Dr. House making a mis-diagnosis out of NF in Episode #309 "Finding Judas"
• The 2002 horror film Cabin Fever surrounds teens plagued by a similar disease to NF.
• In the Scrubs episode "My Lucky Day" (S2E09), Dr. John "JD" Dorian recalls a medical special he saw on television that stated necrotizing fasciitis is often mistaken for cellulitis. Following his instinct, he correctly diagnosed a patient that Dr. Perry Cox had misdiagnosed with cellulitis.
• In the 2005 comedy Fun with Dick and Jane, Dick Harper (Jim Carrey), while attempting to rob a bank as a fake vault inspector, gives 'necrotizing fasciitis caused by an invasive streptococcus' or flesh-eating bacteria as the reason why the usual vault inspector failed to turn up.
• In Greys Anatomy
• In the Star Trek book The Rise and Fall of Khan Noonien Singh, Part II, the titular villain planned to unleash the bacteria upon the world in massive quantities (he and his augment kin were immune).

See also

• Mucormycosis, a rare fungal infection which can present like necrotizing fasciitis
• Toxic shock syndrome
• Cellulitis

External links

• National Necrotizing Fasciitis Foundation official website
• Necrotizing Fasciitis aka The Flesh-Eating Bacteria: True Life Stories of NF Survivors
• HBOT Treatment of necrotizing infections with hyperbaric oxygen therapy.