Necrotizing fasciitis

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Necrotizing fasciitis
Classification and external resources
Necrotizing fasciitis left leg.JPEG
Person with necrotizing fasciitis. The left leg shows extensive redness and necrosis.
ICD-10M72.6
ICD-9728.86
DiseasesDB31119
MedlinePlus001443
eMedicineemerg/332 derm/743
MeSHD019115
 
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Necrotizing fasciitis
Classification and external resources
Necrotizing fasciitis left leg.JPEG
Person with necrotizing fasciitis. The left leg shows extensive redness and necrosis.
ICD-10M72.6
ICD-9728.86
DiseasesDB31119
MedlinePlus001443
eMedicineemerg/332 derm/743
MeSHD019115

Necrotizing fasciitis (/ˈnɛkrəˌtzɪŋ ˌfæʃiˈtɪs/ or /ˌfæs-/) or NF, commonly known as flesh-eating disease, flesh-eating bacteria 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. The most consistent feature of necrotizing fasciitis was first described in 1952 as necrosis of the subcutaneous tissue and fascia with relative sparing of the underlying muscle.[2]

Necrotizing fasciitis progresses rapidly, having greater risk of developing in the immunocompromised due to conditions such as diabetes or cancer. It is a severe disease of sudden onset and is usually treated immediately with surgical debridement and large doses of intravenous antibiotics,[3] with delay in surgical treatment being associated with higher mortality.

Many types of bacteria can cause necrotizing fasciitis (e.g., Group A streptococcus (Streptococcus pyogenes), Staphylococcus aureus, Clostridium perfringens, Bacteroides fragilis, Aeromonas hydrophila[4]). The disease is classified as Type I (polymicrobial, due to a number of different organisms) or Type II (monomicrobial, due to a single infecting organism). The majority of cases of necrotizing fasciitis are polymicrobial, with 25–45% of cases being Type II.[5] Such infections are more likely to occur in people with compromised immune systems secondary to chronic disease.[6]

Historically, most cases of Type II infections have been due to group A streptococcus and staphylococcal species. Since as early as 2001, a particularly difficult to treat form of monomicrobial necrotizing fasciitis has been observed with increasing frequency[7] caused by methicillin-resistant Staphylococcus aureus (MRSA).

Possible sources[edit]

The majority of infections are caused by organisms that normally reside on the individual's skin. These skin flora exist as commensals and infections reflect their anatomical distribution (e.g. perineal infections being caused by anaerobes).

Sources of MRSA may include eating undercooked contaminated meats,[8] working at municipal waste water treatment plants, exposure to secondary waste water spray irrigation,[9] consuming raw products produced from farm fields fertilized by human sewage sludge or septage, in hospital settings from people with weakened immune systems,[10] or sharing/using dirty needles.[11] The risk of infection during regional anaesthesia is considered to be very low, though reported.[12]

Signs and symptoms[edit]

Over 70% of cases are recorded in people with at least one of the following clinical situations: immunosuppression, diabetes, alcoholism/drug abuse/smoking, malignancies, and chronic systemic diseases. For reasons that are unclear, it occasionally occurs in people with an apparently normal general condition.[13]

The infection begins locally at a site of trauma, which may be severe (such as the result of surgery), minor, or even non-apparent. People usually complain of intense pain that may seem excessive given the external appearance of the skin. People initially have signs of inflammation, fever and tachycardia. With progression of the disease, often within hours, tissue becomes progressively swollen, the skin becomes discolored and develops blisters. Crepitus may be present and there may be discharge of fluid, said to resemble "dish-water". 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.

Furthermore, people with necrotizing fasciitis typically have a fever and appear very ill. Mortality rates have been noted as high as 73 percent if left untreated.[14] Without surgery and medical assistance, such as antibiotics, the infection will rapidly progress and will eventually lead to death.[15]

Pathophysiology[edit]

Micrograph of necrotizing fasciitis, showing necrosis (center of image) of the dense connective tissue, i.e. fascia, interposed between fat lobules (top-right and bottom-left of image). H&E stain

"Flesh-eating bacteria" is a misnomer, as in truth, the bacteria do not "eat" the tissue. They destroy the tissue that makes up the skin and muscle by releasing toxins (virulence factors), which include streptococcal pyogenic exotoxins.

Diagnosis[edit]

Necrotising fasciitis producing gas in the soft tissues

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score can be utilized to risk stratify people having signs of cellulitis to determine the likelihood of necrotizing fasciitis being present. It uses six serologic measures: C-reactive protein, total white blood cell count, hemoglobin, sodium, creatinine and glucose. A score greater than or equal to [16] 6 indicates that necrotizing fasciitis should be seriously considered. The scoring criteria are as follows:

Treatment[edit]

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

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 piperacillin/tazobactam, vancomycin, and clindamycin. Cultures are taken to determine appropriate antibiotic coverage, and antibiotics may be changed when culture results are obtained.

People are typically taken to surgery based on a high index of suspicion, determined by the person'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.

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.[19] Amputation of the affected limb(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, though necrosis of internal (thoracic and abdominal) viscera – such as intestinal tissue – is also possible. The associated systemic inflammatory response is usually profound, and most people will require monitoring in an intensive care unit. Because of the extreme nature of many of these wounds and the grafting and debridement that accompanies such a treatment, a burn center's wound clinic, which has staff trained in such wounds, may be utilized.

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, speech pathologists, intensivists, microbiologists and plastic surgeons or oral and maxillofacial surgeons.[20] Maintaining strict asepsis during any surgical procedure and regional anaesthesia techniques is vital in preventing the occurrence of the disease.[21]

Notable cases[edit]

NOTE: It is often incorrectly reported that Jim Henson, creator of the Muppets, died of necrotizing fasciitis. In fact he died of toxic shock syndrome caused by Streptococcus pyogenes.

See also[edit]

References[edit]

  1. ^ Rapini RP, Bolognia JL, Jorizzo JL (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0. 
  2. ^ Wilson, B (April 1952). "Necrotising Fasciitis". Am Surg 18 (4): 416–31. PMID 14915014. 
  3. ^ Jain A, Varma A, Mangalanandan Kumar PH, Bal A (2009). "Surgical outcome of necrotizing fasciitis in diabetic lower limbs". Journal of Diabetic Foot Complications 1 (4): 80–84. 
  4. ^ http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2012/05/16/national/a145331D94.DTL&tsp=1[dead link]
  5. ^ Sarani, Babak; Strong, Michelle; Pascual, Jose; Schwab, C. William (2009). "Necrotizing Fasciitis: Current Concepts and Review of the Literature". Journal of the American College of Surgeons 208 (2): 279–288. doi:10.1016/j.jamcollsurg.2008.10.032. ISSN 1072-7515. 
  6. ^ Kotrappa KS, Bansal RS, Amin NM (April 1996). "Necrotizing fasciitis". American Family Physician 53 (5): 1691–1697. PMID 8623695. 
  7. ^ Lee TC, Carrick MM, Scott BG, et al. (2007). "Incidence and clinical characteristics of methicillin-resistant fasciitis in a large urban hospital". American Journal of Surgery 194 (6): 809–13. doi:10.1016/j.amjsurg.2007.08.047. PMID 18005776. 
  8. ^ "MRSA found in meat". 
  9. ^ "MRSA found in wastewater byproducts". 
  10. ^ "MRSA in hospitals". 
  11. ^ "MRSA from sharing or using dirty needles". 
  12. ^ Singh, Raj Kumar, and Gautam Dutta. "Fatal necrotising fasciitis after spinal anaesthesia." Journal of cutaneous and aesthetic surgery 6.3 (2013): 165.
  13. ^ Pricop M, Urechescu H, Sîrbu A, Urtilă E (Mar 2011). "Fasceita necrozantă cervico-toracică: caz clinic și recenzie a literaturii de specialitate" [Necrotizing cervical fasciitis: clinical case and review of literature]. Revista de chirurgie oro-maxilo-facială și implantologie [Journal of oro-maxillo-facial surgery and implantology] (in Romanian) 2 (1): 1–6. ISSN 2069-3850. 17. Retrieved 2012-04-10. (webpage has a translation button)
  14. ^ Trent JT, Kirsner RS (2002-11-25). "Necrotizing Fasciitis". Medscape. 
  15. ^ "Necrotizing Fasciitis (Flesh-Eating Bacteria)". WebMD. 2011-10-12. 
  16. ^ Crit Care Med. 2004 Jul;32(7):1535-41. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections.
  17. ^ Wong CH, Khin LW, Heng KS, Tan KC, Low CO (2004). "The LRINEC Laboratory Rother soft tissue infections". Critical Care Medicine 32 (7): 1535–1541. doi:10.1097/01.CCM.0000129486.35458.7D. PMID 15241098. 
  18. ^ "LRINEC scoring system for necrotising fasciitis". EMT Emergency Medicine Tutorials. 
  19. ^ 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. Retrieved 2008-05-16. 
  20. ^ 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. 
  21. ^ "Fatal Necrotising Fasciitis After Spinal Anaesthesia". Ncbi.nlm.nih.gov. 2014-01-24. Retrieved 2014-03-01. 
  22. ^ The Once and Future Scourge
  23. ^ Cartwright, K; K. Cartwright, M. Logan, C. McNulty, S. Harrison, R. George, A. Efstratiou, M. McEvoy, and N. Begg (December 1995). "A cluster of cases of streptococcal necrotizing fasciitis in Gloucestershire". Epidemiol Infect. 3 187 (3): 387–397. PMC 2271581. 
  24. ^ Dixon, Bernhard (11 March 1996). "Microbe of the Month: What became of the flesh-eating bug?". Independent. Retrieved 28 May 2013. 
  25. ^ "Moorad's life changed by rare disease
  26. ^ Cornell Discusses His Recovery from Necrotizing Fasciitis with Reporters
  27. ^ "In Memoriam – Alexandru A. Marin (1945–2005)", ATLAS eNews, December 2005 (accessed 5 November 2007).
  28. ^ Flesh-eating bug killed top economist in 24 hours
  29. ^ Before I was so rudely interrupted
  30. ^ R. W. Johnson "Diary", London Review of Books, 6 August 2009, p41
  31. ^ "Slayer Guitarist Jeff Hanneman: Official Cause Of Death Revealed - May 9, 2013". Blabbermouth.net. Roadrunner Records. Retrieved 10 May 2013. 
  32. ^ "The Plastinated Man" post on Peter Watts's blog
  33. ^ /view/full_story/18504981/article-UWG-student-in--dire--condition-after-zip-line-injury?instance=west_ga_news "UWG student in 'dire' condition after zip line injury". Tallapoosa-Journal.com. Retrieved May 16, 2012. 
  34. ^ "Aimee's Accident". Retrieved July 19, 2014. 
  35. ^ Irish Independent: Woman killed by flesheating bug, 28 June 2013. Visited: 1 July 2013
  36. ^ Michelle Robinson. "Family Counts Blessings After Superbug Scare". Stuff.co.nz. Retrieved 2013-10-01. 
  37. ^ CBS Late Show 2014-02-05
  38. ^ ABCNews July 30, 2014: "Dangerous bacteria: Vibro Vulnificus in Florida ocean hospitalizes 32, kills 10"

External links[edit]