Necrotizing fasciitis

Necrotizing fasciitis
Classification and external resources
Caucasian male with necrotizing fasciitis. The left leg shows extensive redness and necrosis.
ICD-10	M72.6
ICD-9	728.86
MedlinePlus	001443
eMedicine	emerg/332 derm/743
MeSH	D019115

Necrotizing fasciitis (NF), commonly known as flesh-eating disease or Flesh-eating bacteria syndrome,^[1] is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue.

Necrotizing fasciitis is a quickly progressing and severe disease of sudden onset and is usually treated immediately with high doses of intravenous antibiotics.

Type I describes a polymicrobial infection, whereas Type II describes a monomicrobial infection. Many types of bacteria can cause necrotizing fasciitis (e.g., Group A streptococcus (Streptococcus pyogenes), Staphylococcus aureus, Vibrio vulnificus, Clostridium perfringens, Bacteroides fragilis). Such infections are more likely to occur in people with compromised immune systems.^[2]

Historically, Group A streptococcus made up most cases of Type II infections. However, since as early as 2001, another serious form of monomicrobial necrotizing fasciitis has been observed with increasing frequency.^[3] In these cases, the bacterium causing it is methicillin-resistant Staphylococcus aureus (MRSA), a strain of S. aureus that 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.

Several studies^[4] have demonstrated a link between absorption of non-steroidal anti-inflammatory drugs and flesh-eating disease, though it has not been established whether the drugs just masked the symptoms or were a cause per se.

Signs and symptoms

Over 70% of cases are recorded in patients with one of the following clinical situations: immunosuppression, diabetes, alcoholism/drug abuse, malignancies, and chronic systemic diseases. It occasionally occurs in people with an apparently normal general condition.^[5]

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 excessive given the external appearance of the skin. With progression of the disease, often within hours, tissue becomes swollen. 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, develop 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.^[6] Without surgery and medical assistance, such as antibiotics, the infection will rapidly progress and will eventually lead to death.^[7]

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 and severe systemic illness (Toxic shock syndrome).

Diagnosis

LRINEC score

Free air in the soft tissues due to necrotizing fasciitis

Necrotising fascitis causing air in soft tissues

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score can be utilized to risk stratify patients presenting with signs of cellulitis to determine the likelihood of necrotizing fasciitis being present. It uses six serologic measures: C-reactive protein, total white cell count, hemoglobin, sodium, creatinine and glucose. A score greater than 6 indicates that necrotizing fasciitis should be seriously considered. The scoring criteria are as follows

• CRP (mg/L) >150 - 4 points
• WBC count (per mm3)
  • <15 - 0 points
  • 15-25 - 1 point
  • >25 - 2 points
• Hemoglobin (g/dL)
  • >13.5 - 0 points
  • 11-13.5 - 1 point
  • <11 - 2 points
• Sodium (mmol/L) <135 - 2 points
• Creatinine (umol/L) >141 - 2 points
• Glucose (mmol/L) >10 - 1 point^[8][9]

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.^[10] 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.

Treatment for necrotizing fasciitis may involve an interdisciplinary care team. For example, in the case of a necrotizing fasciitis involving the head and neck, the team could include otolaryngologists, intensivists, microbiologists and plastic surgeons.^[11]

Notable people afflicted

• King Herod the Great of Judea may have suffered from Fournier gangrene (necrotizing fasciitis of the groin and genitalia) at the time of his death, as suggested in a "historical autopsy."^[12][13]
• Lucien Bouchard, former premier of Québec, Canada, who became infected in 1994 while leader of the federal official opposition Bloc Québécois party, lost a leg to the illness.^[14]
• 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.^{[citation needed]}
• 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.^[15]
• Eric Allin Cornell, winner of the 2001 Nobel Prize in Physics, lost his left arm and shoulder to the disease in 2004.^[16]
• Jan Peter Balkenende, former Prime Minister of the Netherlands was infected in 2004. He was in the hospital for several weeks but recovered fully.^[17]
• 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.^[18]
• 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.^[19]
• 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.^[20]
• 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.^[21]
• Jeff Hanneman, guitarist for the thrash-metal band Slayer, contracted the disease in early 2011. He was allegedly infected after being bitten by a spider.^[22]
• Peter Watts, Canadian science fiction author, contracted the disease in early 2011. On his blog, Watts reported, "I’m told I was a few hours away from being dead.... If there was ever a disease fit for a science fiction writer, flesh-eating disease has got to be it. This fucker spread across my leg as fast as a Star Trek space disease in time-lapse."^[23]

See also

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

References

1. ^ Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0. 
2. ^ Kotrappa, K S; R S Bansal, N M Amin (1996-04). "Necrotizing fasciitis". American Family Physician 53 (5): 1691-1697. ISSN 0002-838X. http://www.ncbi.nlm.nih.gov/pubmed/8623695. 
3. ^ Lee TC, Carrick MM, Scott BG, et al. (2007). "Incidence and clinical characteristics of methicillin-resistant fasciitis in a large urban hospital". Am J Surg 194 (6): 809–13. doi:10.1016/j.amjsurg.2007.08.047. PMID 18005776. 
4. ^ Voss, Lesley (November 2000). "Necrotising Fasciitis Associated with Non-Steroidal Anti-Inflammatory Drugs". New Zealand Medicines and Medical Devices Safety Authority. http://www.medsafe.govt.nz/Profs/puarticles/necf.htm. 
5. ^ Pricop M, Urechescu H, Sîrbu A, Urtilă E (Feb 2011). "Necrotizing cervical fasciitis: clinical case and review of literature". Revista de Chirurgie Oro-Maxilo-Facială și Implantologie 2 (1): 1–6. http://www.revistaomf.ro/index.php?section=Article&ID=17. (in Romanian, webpage has a translation button)
6. ^ http://www.medscape.com/viewarticle/444061
7. ^ Necrotizing Fasciitis (Flesh-Eating Bacteria)
8. ^ . PMID 15241098. 
9. ^ [1]
10. ^ Escobar SJ, Slade JB, Hunt TK, Cianci P (2005). "Adjuvant hyperbaric oxygen therapy (HBO2) for treatment of necrotizing fasciitis reduces mortality and amputation rate". Undersea Hyperb Med 32 (6): 437–43. PMID 16509286. http://archive.rubicon-foundation.org/4061. Retrieved 2008-05-16. 
11. ^ Malik V; Gadepalli, C; Agrawal, S; Inkster, C; Lobo, C (2010). "An Algorithm for Early Diagnosis of Cervicofacial Necrotizing Fasciitis". Eur Arch. Otorhinolaryngol. 267 (8): 1169–77. doi:10.1007/s00405-010-1248-5. PMID 20396897. 
12. ^ Medina P, Gonzalez-Rivas F, Blanco A, Tejido S, Leiva G (2009). "Fournier's Gangrene: Baurienne, 1764 and Herod the Great, 4 B.C.". European Urology Supplements 8 (5): 121–121. doi:10.1016/S1569-9056(09)60011-7. 
13. ^ "Mystery of Herod's death 'solved'". CNN. 2002-01-25. http://archives.cnn.com/2002/HEALTH/conditions/01/25/king.herod/index.html. 
14. ^ The Once and Future Scourge
15. ^ "Moorad's life changed by rare disease
16. ^ Cornell Discusses His Recovery from Necrotizing Fasciitis with Reporters
17. ^ PM: foot infection could have been fatal
18. ^ "In Memoriam - Alexandru A. Marin (1945 - 2005)", ATLAS eNews, December 2005 (accessed 5 November 2007).
19. ^ Flesh-eating bug killed top economist in 24 hours
20. ^ Before I was so rudely interrupted
21. ^ R. W. Johnson "Diary", London Review of Books, 6 August 2009, p41
22. ^ AOL - Slayer guitarist comes down with flesh-eating disease
23. ^ "The Plastinated Man" post on Peter Watts's blog

External links

• Necrotizing fasciitis at the Open Directory Project