Necrotizing fasciitis is a relatively rare and serious soft tissue infection that differs from streptococcal necrosis and is often a mixed infection of multiple bacteria. rea and Wyrick confirmed that the causative organisms include gram-positive hemolytic streptococci, staphylococcus aureus, gram-negative bacteria, and anaerobic bacteria. In the past, anaerobic bacteria were often not found due to poor culture techniques, but in recent years it was confirmed that anaerobic bacteria such as Bacteroidetes and Streptococcus pepticus and Coccidioides are often one of the causative agents of the disease, but rarely are they purely anaerobic infections. guiliano reported 16 cases of necrotizing fasciitis with 75 bacterial species cultured, 15 cases with at least one parthenogenic streptococcus, 10 cases of Bacteroidetes and 8 cases of Streptococcus pepticus. In the cases of Stone Martin (1972), Gram-negative aerobic bacilli accounted for 62%, enterococci 19%, had anaerobic streptococci 51%, and combined bacteriophages 24%, but no β-hemolytic streptococci were seen. Although the case subjects of both groups differed, the results all proved that necrotizing fasciitis is often a synergistic effect of aerobic and anaerobic bacteria, with parthenogenic bacteria first consuming oxygen in the infected tissue, reducing the redox potential difference (Eh) of the tissue, and the enzymes produced by the bacteria decomposing H2O2, thus favoring the growth and reproduction of anaerobic bacteria. Depending on the condition, necrotizing fasciitis can be divided into two types: one in which the causative bacteria spread through trauma or primary lesions, causing a sudden deterioration and rapid necrosis of soft tissue. The other type has a slower progression and is predominantly cellulitis, with multiple skin ulcers, thin and oddly smelly pus, a dishwater-like appearance, extensive subterranean skin around the ulcers, and a twisted pronunciation and local sensation of numbness or pain, characteristics that are not common in cellulitis. Patients often have significant toxemia with chills, hyperthermia, and hypotension. Hypocalcemia may occur in cases of extensive subcutaneous tissue necrosis. Bacteriological examination is of particular importance for diagnosis, especially smear examination of wound pus. The differential diagnosis of necrotizing infection can be found in Table 62. The key to treatment of necrotizing fasciitis is early and thorough dilation surgery with adequate incision of the subcutaneous margin and removal of necrotic tissue, including necrotic subcutaneous adipose tissue or superficial fascia, but the skin can usually be preserved. The wound is left open and irrigated with 3% hydrogen peroxide or 1:5000 potassium permanganate solution, loosely filled with gauze, or several polyethylene catheters are inserted for postoperative irrigation. Baxter recommends irrigation with saline containing neomycin 100 mg/L and polymyxin B 100 mg/L, while others recommend carbenicillin or 0.5% metronidazole solution. The drug change should be done to speed up the removal of necrotic tissues, and the necrotic tissues found need to be re-invasive. Bacterial cultures should be repeated at the time of dressing change for early detection of secondary bacteria such as Pseudomonas aeruginosa, Serratia marcescens, or Candida. The causative agents of necrotizing fasciitis include Enterobacter spp, Enterococcus spp, and anaerobic Streptococcus and Bacteroides spp. A combination of ampicillin should be used to control Enterococcus and anaerobic Streptococcus Table 6-2 Differential diagnosis of necrotizing infections of subcutaneous tissue and skin Modern medical research has led to the medical term “necrotizing fasciitis” for this flesh-eating pathogen that coagulates the skin ( Necrotising Fasciitis, which kills 1,500 people a year in the United States alone, can kill a person’s muscles in a matter of hours by releasing toxins in the infected body, turning them into a bloody mess. The incidence of the disease is 5% in healthy conditions when some of the similar symptoms of necrotizing fasciitis are present, but some are misdiagnosed as cellulitis. Although biopsy is required to confirm the diagnosis, in some cases biopsy can be omitted and surgery performed directly, as the disease can spread rapidly and later can lead to extensive extension or even amputation. “Time is of the essence!” One second could change the fate of a person’s life!!!