From the Guidelines
Diagnosis of necrotizing fasciitis requires a high index of suspicion and prompt recognition of clinical features, with immediate surgical debridement and broad-spectrum antibiotics being essential for treatment, as delayed treatment significantly increases mortality. Patients typically present with severe pain disproportionate to physical findings, along with erythema, edema, and skin changes that may rapidly progress to bullae, skin necrosis, and crepitus. Laboratory findings often include leukocytosis, elevated C-reactive protein, hyponatremia, and elevated creatine kinase.
Key Diagnostic Features
- The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score can aid diagnosis, with a score ≥6 suggesting necrotizing fasciitis, although it should not be used to rule out the condition due to its poor sensitivity 1.
- Imaging studies like CT or MRI can show fascial thickening, gas in soft tissues, or fluid collections, but should not delay surgical intervention if clinical suspicion is high.
- Definitive diagnosis requires surgical exploration with findings of grayish necrotic fascia, lack of bleeding, lack of resistance to blunt dissection, and "dishwater" purulent discharge.
Treatment Approach
- Immediate surgical debridement is essential, along with broad-spectrum antibiotics (typically a combination of piperacillin-tazobactam or meropenem, plus vancomycin, and clindamycin for its anti-toxin effects) 1.
- The Fournier’s Gangrene Severity Index (FGSI) score can be used for prognosis and risk stratification, with a score >9 indicating a high probability of death 1.
Important Considerations
- Early diagnosis is critical, as mortality increases significantly with delayed treatment, with the condition progressing rapidly over hours.
- A high index of suspicion and prompt recognition of clinical features are essential for timely diagnosis and treatment.
- The use of scoring systems, such as the LRINEC and FGSI, can aid in diagnosis and risk stratification, but should not delay surgical intervention if clinical suspicion is high.
From the Research
Diagnosis of Necrotizing Fasciitis
- The diagnosis of necrotizing fasciitis (NF) is often missed or delayed due to the lack of specific clinical features in the initial stage of the disease 2, 3, 4.
- A high index of clinical suspicion is the most important tool for early diagnosis of NF 2.
- Laboratory tests, such as the LRINEC score, can help depict the severity of the disease, but are not definitive for diagnosis 3.
- Imaging and intraoperative tissue culture can also aid in diagnosis, with the latter being the gold standard 5.
Clinical Presentation
- NF is characterized by subtle, rapid onset of spreading inflammation and necrosis starting from the fascia, muscles, and subcutaneous fat, with subsequent necrosis of the overlying skin 2.
- Common symptoms include local pain and tenderness, with septic shock occurring in some cases 3.
- The disease can affect various parts of the body, including the perineum, lower limbs, upper limbs, and abdominal wall 3.
Diagnostic Tools
- Various diagnostic tools have been described to facilitate and hasten the diagnosis of NF, including laboratory markers and imaging 2, 6, 5.
- The LRINEC score is a laboratory-based scoring system that can help identify patients at high risk of NF 3.
- Intraoperative tissue culture is considered the gold standard for diagnosis 5.