Necrotizing fasciitis is part of a spectrum of soft-tissue infections first described by Hippocrates in the fifth century B.C. as a complication of "erysipelas."1 Confederate Army surgeon Joseph Jones described it as "hospital gangrene" during the Civil War, during which 46% of the 2,642 soldiers afflicted died from its complications.2 Meleney reported a series of 20 patients in 1924 as having "hemolytic streptococcal gangrene," later called Meleney's gangrene.3 Wilson coined the modern term necrotizing fasciitis in 1952.2 Recent outbreaks of NF have resulted in sensational headlines, such as "Killer Bug," "Flesh-Eating Bacteria" and "Galloping Gangrene."
NF is a soft-tissue infection of subcutaneous tissue and fascia. In contrast, other soft-tissue infections are more superficial skin infections: cellulitis, erysipelas, impetigo, folliculitis, ecthyma, furunculosis and carbunculosis.4 Myonecrosis (clostridial and nonclostridial) is a soft-tissue infection with rapid necrosis of muscles and delayed involvement of overlying skin and soft tissues. NF involves the superficial fascia, subcutaneous fat (with nerves and vascular structures) and deep fascia.4 There is thrombosis of microvasculature and absence of myonecrosis.5
Giuliano and colleagues defined two bacteriologic types of NF in 1977.5 The clinical picture of the types is indistinguishable on gross or microscopic examination. Classification of NF has evolved over time. Types of NF are:
Type A, polymicrobial, involves non-group A beta-hemolytic streptococcal infection plus anaerobes and/or facultative anaerobes. It is frequently a postoperative, often abdominal infection with gas-forming organisms: anaerobic Bacteroides, Peptococcus and Clostridium; and facultative anaerobic bacteria such as alpha-hemolytic Streptococcus, Escherichia coli, Enterobacter, Klebsiella or Proteus species.6
Type B, monomicrobial group A beta-hemolytic streptococcal infection, is seen occasionally in conjunction with Staphylococcus aureus.6,7 It is also known as beta-hemolytic streptococcal gangrene.5 Infections involving an extremity more commonly are monomicrobial.4
Type C infections are caused by marine Vibrio species (Gram-negative rods), such as V. vulnificus (the most virulent). The portal of entry for infection is through an abrasion or puncture wound caused by fish, by a cut or by an insect bite. Pathologic Vibrio species synthesize extracellular toxins that mediate soft-tissue damage in NF.4
NF caused by Aeromonas hydrophila has also been reported.8 It is an oxidase-positive, facultative anaerobic, unipolar, flagellated, Gram-negative bacillus found in fresh or brackish water in many parts of the United States.
In one report, 98% of 83 NF patients had bacterial growth with an average of 4.6 isolates per specimen. Mixed aerobic-anaerobic flora were recovered in 68% of specimens.9
1. Descamps V, Aitken J, Lee MG. Hippocrates on necrotising fasciitis. Lancet. 1994;344:556.
2. Wilson B. Necrotizing fasciitis. Am Surg. 1952;18:416-431.
3. Meleney FL. Hemolytic streptococcus gangrene. Arch Surg. 1924;9:317-364.
4. Green RJ, Dafoe DC, Raffin TA. Necrotizing fasciitis. Chest. 1996;110:219-229.
5. Giuliano A, Lewis F Jr, Hadley K, Blaisdell FW. Bacteriology of necrotizing fasciitis. Am J Surg. 1977;134:52-57.
6. Angel MF, Zhang F, Jones M, Henderson J, Chapman SW. Necrotizing fasciitis of the upper extremity resulting from a water moccasin bite. South Med J. 2002;95:1090-1094.
7. Hoadley DJ, Mark EJ. Case Records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 28-2002. A 35-year-old long-term traveler with a rapidly progressive soft-tissue infection. N Engl J Med. 2002;347:831-837.
8. Minnaganti VR, Patel PJ, Iancu D, Schoch PE, Cunha BA. Necrotizing fasciitis caused by Aeromonas hydrophila. Heart Lung. 2000;29:306-308.
9. Brook I, Frazier EH. Clinical and microbiological features of necrotizing fasciitis. J Clin Microbiol. 1995;33:2382-2387.