A 9-day-old neonate presented with high fever, moaning, and slightly indurated swelling with bluish discoloration on the back (Figure 106-1). Within 12 hours, there was vesiculation and purplish discoloration. The infant was diagnosed with necrotizing fasciitis and surgery was consulted immediately. The first surgical exploration and débridement and shows the underlying muscle and necrotic borders. Both blood and tissue cultures grew Staphylococcus aureus. Multiple surgical explorations and débridement were performed followed by skin grafting during recovery. The infant survived with scarring but no other sequelae.

A 16-year-old female presented with necrotizing fasciitis of the left gluteal region following an intramuscular injection received in rural India. She was febrile and in septic shock. The entire left gluteal region had full thickness necrosis and was emitting a foul odor. The skin was violaceous with purple bullae and areas of exfoliation. Previous attempts at incision and drainage were not helpful. She was treated with intravenous fluids, antibiotics and full-thickness extensive surgical debridement in the operating room. She became afebrile and hemodynamically stable. Her subsequent treatment consisted of negative pressure wound therapy followed by skin grafting. She survived with scarring and contour deformities but no other sequelae (Figure 106-2).

Necrotizing fasciitis (NF) is a rapidly progressive infection of the deep fascia, with necrosis of the subcutaneous tissues. In children, it usually occurs after surgery, trauma, or varicella infection. Patients have erythema and pain disproportionate to the physical findings. Immediate surgical debridement and antibiotic therapy should be initiated.¹

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  Flesh-eating bacteria, necrotizing soft-tissue infection (NSTI), suppurative fasciitis, hospital gangrene, and necrotizing erysipelas. Fournier gangrene is a type of NF or NSTI in the genital and perineal region.²

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  Overall incidence of NF in children (<16 years of age) is 2.93 cases per million population per year, according to a recent population-based active surveillance study from Canada; incidence is 0.81 per million for non–Group A Streptococcus-related cases, and 2.12 per million for Group A Streptococcus (GAS)-related cases.³

  
  
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  For non-GAS-related cases, NF typically occurs in children with underlying medical conditions, such as diabetes mellitus, trauma or recent surgery. ³

  
  
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  NF caused by Streptococcus pyogenes is the most common form of NF in children and adults.³

  
  
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  Non-GAS-related cases are most common in infants less than one-year of age; pre-existing risk factors, such as prematurity, are common, and many of these cases occur in association with omphalitis or circumcision.

  
  
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  Most cases of GAS-related NF are associated with varicella (Figure 106-3).^3,4

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  Type I NF is a polymicrobial infection with aerobic and anaerobic bacteria:

  
  
  
  
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    Frequently caused by enteric Gram-negative pathogens including Enterobacteriaceae organisms and Bacteroides.

    
    
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    Can occur with Gram-positive organisms such as non-group A streptococci and Peptostreptococcus.⁵

    
    
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    Saltwater variant can occur with penetrating trauma or an open wound contaminated with saltwater containing marine vibrios. Vibrio vulnificus is the most virulent.⁶

    
    
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    Up to 15 pathogens have been isolated in a single wound.

    
    
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    Average of five different isolates per wound.⁷

  
  
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  Type II NF is the most common form in children and is generally a monomicrobial infection caused by GAS:

  
  
  
  
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    May occur in combination with Staphylococcus aureus.

    
    
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    Methicillin-resistant S. aureus is no longer a rare cause of NF.5

    
    
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    GAS may produce pyrogenic exotoxins, which act as superantigens to stimulate production of tumor necrosis factor (TNF)-a, TNF-b, interleukin (IL)-1, IL-6, and IL-2.⁷