TABLE 5 Necrotizing Fasciitis: Key Points
NF is a rare, life-threatening, soft-tissue infection characterized by rapidly spreading inflammation and necrosis of the skin, subcutaneous fat, and fascia
After an incubation period of 1-4 days, an acute onset of symptoms with moderate to marked toxemia, a putrid discharge, and pain out of proportion to the physical examination findings
Clinical manifestations include extensive dissection and necrosis of the superficial and often the deep fascia. The infection undermines adjacent tissue and leads to marked systemic toxicity
Thrombosis of subcutaneous blood vessels leads to necrosis of the overlying skin
Most cases of fasciitis follow surgery or minor trauma. The highest incidence is seen in patients with small vessel diseases such as diabetes mellitus
When careful bacteriologic techniques are used, anaerobes, particularly Peptostreptococcus, Bacteroides, and Fusobacterium species, are found in 50-60% of cases. Aerobic organisms, especially Streptococcus pyogenes, Staphylococcus aureus, and members of the Enterobacteriaceae have also been isolated
Most infections are mixed aerobic-anaerobic infections, but a type of NF caused solely by S. pyogenes has been reported and is referred to by the lay press as "flesh eating bacteria"
Symptomatology (by location of infection)
Initial local pain is replaced by numbness or analgesia as the infection involves the cutaneous nerves
Clinically, the hallmarks of mixed aerobic-anaerobic soft tissue infections are tissue necrosis, a putrid discharge, gas production, the tendency to burrow through soft tissue and fascial planes, and the absence of classic signs of tissue inflammation
A Gram stain of tissue fluid and blood cultures should be obtained to assist in guiding antibiotic therapy
Radiologic testing may detect air within the tissue, highly suggestive of NF
Treatment includes broad-spectrum antibiotic coverage, nutritional supplements, hemodynamic support, wound care, and prompt surgical debridement
Untreated, NF has been noted to have an extremely high mortality rate, ranging from 80-100%, and even with rapid intervention and treatment, mortality remains approximately 30-50%
Abbreviation: NF, necrotizing fasciitis.
postpartum patients, or a combination of these factors (16). The unifying thread among these risk factors appears to be a compromised fascial blood supply coupled with the introduction of exogenous microbes. However, various studies have reported that 13% to 31% of patients were previously healthy individuals with no identifiable risk factors (15). The incidence of NF in adults has been reported to be 0.40 cases per 100,000 population, while the incidence in children is 0.08 cases per 100,000 population (16).
Was this article helpful?