What is the diagnosis and treatment for Necrotizing Fasciitis (NF)?

From the Guidelines

Necrotizing fasciitis requires immediate medical attention with prompt surgical debridement and broad-spectrum intravenous antibiotics to reduce morbidity and mortality. The treatment of necrotizing fasciitis involves a combination of surgical intervention and antimicrobial therapy. According to the practice guidelines for the diagnosis and management of skin and soft tissue infections by the Infectious Diseases Society of America 1, surgical intervention is the primary therapeutic modality in cases of necrotizing fasciitis and is indicated when this infection is confirmed or suspected.

Key Considerations

• Features suggestive of necrotizing fasciitis include clinical findings such as profound toxicity, fever, hypotension, or advancement of the skin and soft tissue infection (SSTI) during antibiotic therapy, skin necrosis with easy dissection along the fascia by a blunt instrument, or presence of gas in the soft tissues.
• Most patients with necrotizing fasciitis should return to the operating room 24–36 hours after the first debridement and daily thereafter until the surgical team finds no further need for debridement.
• Empiric treatment of polymicrobial necrotizing fasciitis should include agents effective against both aerobes, including MRSA, and anaerobes, such as vancomycin, linezolid, or daptomycin combined with one of the following options: piperacillin-tazobactam, a carbapenem, ceftriaxone plus metronidazole, or a fluoroquinolone plus metronidazole 1.

Antibiotic Regimens

• A typical antibiotic regimen includes a combination of piperacillin-tazobactam (3.375g IV every 6 hours), vancomycin (15-20 mg/kg IV every 8-12 hours), and clindamycin (600-900 mg IV every 8 hours) to cover various potential pathogens including Group A Streptococcus, Staphylococcus aureus, and anaerobes.
• For documented group A streptococcal necrotizing fasciitis, treatment with both clindamycin and penicillin is recommended, as clindamycin suppresses streptococcal toxin and cytokine production 1.

Supportive Care

• Supportive care with IV fluids, pain management, and possibly intensive care monitoring is necessary to manage the infection and its complications.
• The infection typically begins with intense pain, swelling, and redness in an area, often following minor trauma, and rapidly worsens with skin discoloration, blisters, and systemic symptoms like fever and confusion.
• Early recognition and aggressive surgical intervention are the most critical factors in improving survival, as the mortality rate remains high (20-40%) even with treatment, primarily because the infection spreads rapidly through fascial planes with minimal external signs until advanced 1.

From the Research

Definition and Characteristics of Necrotizing Fasciitis

• Necrotizing fasciitis is a life-threatening soft tissue infection characterized by a rapid spreading infection of the subcutaneous tissue and in particular the fascia 2, 3.
• It is a medical and surgical emergency that requires immediate attention and treatment 3, 4.
• The infection can affect various parts of the body, including the skin and subcutaneous tissues of lower and upper limbs, perineal area, and the abdominal wall 5.

Diagnosis and Clinical Presentation

• Early diagnosis of necrotizing fasciitis is crucial, but it can be missed or delayed due to variable and nonspecific clinical presentation 3, 5, 4.
• The most common symptoms include local pain and tenderness, and septic shock can occur in severe cases 5.
• Laboratory tests, such as the LRINEC score, can be used to depict the severity of the disease and guide treatment decisions 5.

Treatment and Management

• The treatment of necrotizing fasciitis requires a multifaceted approach, consisting of surgical source control with immediate surgical debridement, life support, clinical monitoring, and antimicrobial therapy 2, 3, 6.
• Broad-spectrum antibiotics, such as piperacillin-tazobactam or a carbapenem, are recommended for initial treatment, and newer antibiotics, such as ceftolozane-tazobactam and ceftazidime-avibactam, may be considered as alternatives 6.
• Surgical debridement is a crucial component of treatment, and repetitive debridement may be necessary in some cases 2, 5.
• Amputation of the affected limb may be required in severe cases, and diabetes mellitus has been identified as a risk factor for amputation 2, 5.