Necrotizing Fasciitis: Recognition, Resuscitation and Emergency Management

Learning objectives

• Define necrotizing fasciitis and distinguish it from cellulitis, abscess and other soft-tissue infections.
• Recognise risk factors, early disproportionate pain, systemic toxicity, skin changes and Fournier’s gangrene.
• Perform ABCDE, sepsis and limb/perineal assessment, obtain cultures and communicate urgency.
• Describe emergency fluids, broad-spectrum antibiotics, toxin suppression, surgery, ICU and wound care.
• Plan nursing, infection-control, rehabilitation, prevention and patient/family education.

Definition and pathophysiology

Necrotizing fasciitis is infection and thrombosis of the superficial fascia, deep fascia and surrounding subcutaneous tissue. Bacteria release enzymes and toxins that destroy tissue, impair perfusion and spread along fascial planes. Infection may be polymicrobial (aerobic and anaerobic organisms) or monomicrobial, commonly involving group A Streptococcus, Staphylococcus aureus, Gram-negative organisms or anaerobes. Type I disease is often polymicrobial; type II is commonly group A streptococcal or staphylococcal.

As fascia becomes necrotic, analgesia-resistant pain, oedema, systemic inflammatory response, capillary leak and septic shock develop. Skin may initially appear relatively normal because the infection spreads beneath it. Later there may be bullae, dusky or purple skin, anaesthesia, crepitus, foul drainage and black necrosis.

Risk factors and portals of entry

Clinical features

• Severe pain out of proportion to the visible lesion, pain beyond the erythematous margin or rapidly escalating analgesic requirement.
• Rapidly spreading redness, swelling, warmth, tense skin and oedema; fever, tachycardia, tachypnoea, weakness or confusion.
• Skin anaesthesia from nerve destruction, bullae, dusky/purple/grey or black patches, crepitus and foul or “dishwater” discharge.
• Sepsis or shock: hypotension, delayed capillary refill, oliguria, altered mental state, rising lactate and organ dysfunction.
• Fournier’s gangrene: severe genital/perineal pain or swelling, skin discoloration, crepitus, urinary difficulty or systemic toxicity.

First contact and infection control

1. Use gloves, gown, eye/face protection and hand hygiene; cover draining wounds and isolate contaminated materials according to facility policy.
2. Place the patient in a resuscitation area, remove constricting clothing/jewellery and protect the limb or perineum from pressure.
3. Activate emergency surgery, anaesthesia, infectious-disease/medical and ICU teams. State “suspected necrotizing soft-tissue infection with possible sepsis.”
4. Keep nil by mouth for likely debridement; provide analgesia, antiemetic and reassurance without delaying surgery.
5. Mark the edge of erythema with time/date for trend, but do not let marking or imaging delay theatre.

ABCDE and sepsis assessment

A — Airway

• Assess consciousness, vomiting, facial/neck infection and airway swelling. Prepare early airway support for sepsis, shock or anaesthetic transfer.

B — Breathing

• Measure respiratory rate, SpO₂ and work of breathing; tachypnoea may indicate sepsis, acidosis or pneumonia.
• Give oxygen for hypoxaemia/distress and prepare ventilation support if respiratory failure develops.

C — Circulation

• Check pulse, BP, capillary refill, temperature, urine output, lactate and peripheral perfusion.
• Insert two IV lines where possible, collect blood cultures/labs and start isotonic crystalloid for shock under sepsis protocol.
• Activate blood/vasopressor/critical-care support when hypotension persists, especially with extensive debridement or bleeding.

D — Disability

• Record AVPU/GCS and bedside glucose; confusion, agitation or drowsiness may indicate sepsis, hypoglycaemia or shock.
• Assess pain, sensation and motor function of the affected limb; new numbness suggests advanced tissue injury.

E — Exposure

• Expose and inspect the entire limb/body, perineum, surgical wounds and pressure areas while maintaining dignity and warmth.
• Look for crepitus, bullae, anaesthesia, rapidly advancing margin, foul drainage and compartment/vascular compromise.

Focused history and examination

Differential diagnosis

• Cellulitis or erysipelas: superficial infection, usually slower and without severe pain beyond visible changes.
• Abscess: localised fluctuance; can coexist with or progress to necrotizing infection.
• Severe diabetic foot infection, infected ulcer or osteomyelitis.
• Compartment syndrome, deep-vein thrombosis, acute limb ischaemia, pyomyositis or traumatic haematoma.
• Vasculitis, calciphylaxis, pyoderma gangrenosum, necrotic tumour or severe allergic reaction.
• Do not use a normal white count, normal temperature, normal early X-ray or low LRINEC score to exclude necrotizing fasciitis.

Investigations

• Blood cultures before antibiotics when this causes no delay, full blood count, electrolytes, urea/creatinine, glucose, CRP, lactate, blood gas, coagulation and CK.
• Deep tissue/wound cultures are obtained during surgery; superficial swabs may not reflect the deep pathogen.
• Plain radiograph may show gas but a normal film does not exclude disease. CT/MRI can define extent only if the patient is stable and imaging will not delay exploration.
• Ultrasound may identify fluid or gas but cannot safely rule out fascial infection.
• Assess renal function, tetanus status, pregnancy, HIV/diabetes and nutrition to guide treatment.

Immediate medical management

1. Source control: urgent surgical consultation and aggressive exploration/debridement. CDC states primary treatment is early surgery and removal of necrotic tissue, coupled with broad-spectrum IV antibiotics.
2. Antibiotics: start broad-spectrum parenteral therapy immediately according to the local antimicrobial guideline, covering Gram-positive, Gram-negative and anaerobic organisms, including MRSA where indicated.
3. Toxin suppression: clindamycin is commonly added for documented or strongly suspected group A streptococcal disease; IDSA recommends penicillin plus clindamycin for confirmed GAS necrotizing fasciitis.
4. Resuscitation: treat sepsis/shock with isotonic fluid, oxygen when indicated, vasopressors and organ support in ICU.
5. Tetanus/wound care: update tetanus prophylaxis and cover wounds with sterile dressings; do not close infected necrotic wounds.

Surgical management

• Explore beyond the visible skin changes, follow fascial planes and remove all devitalised tissue until healthy bleeding tissue is reached.
• Leave the wound open for drainage and planned reassessment; CDC notes re-inspection around 24 hours is commonly required to confirm adequate debridement.
• Repeat debridement is often necessary; amputation may be life-saving when tissue cannot be preserved or infection is uncontrolled.
• Fournier’s gangrene may require extensive perineal, genital, colorectal or urological source control and urinary/faecal diversion decisions.
• After infection control, reconstruction may include negative-pressure therapy, grafts, flaps and rehabilitation.

Nursing and EMT interventions

• Trend vital signs, pain, skin margin, neurovascular status, urine output, lactate, glucose, renal function and response to fluids/antibiotics.
• Use strict aseptic technique, correct PPE, wound isolation and safe disposal; protect staff from drainage and sharps.
• Administer antibiotics on time, check allergies/renal dosing and monitor for anaphylaxis, nephrotoxicity, diarrhoea and line complications.
• Maintain warming, pressure relief, nutrition, glycaemic control and analgesia; coordinate repeated theatre trips.
• Provide psychological support, explain staged surgery and involve family with consent; prepare for body-image, amputation and rehabilitation needs.

Complications

• Septic shock, disseminated intravascular coagulation, acute kidney injury, respiratory failure and multi-organ failure.
• Compartment syndrome, limb ischaemia, tissue loss, amputation and severe scarring.
• Necrotizing myositis, toxic shock syndrome, bacteremia and recurrent infection.
• Hypothermia, hypoglycaemia/hyperglycaemia, malnutrition, pressure injury and venous thromboembolism.
• Post-traumatic stress, depression, grief, sexual/urinary dysfunction and long-term rehabilitation needs.

Prevention and patient education

• Clean and cover wounds promptly, seek care for spreading redness or increasing pain and do not squeeze abscesses.
• Control diabetes, stop smoking, maintain nutrition and inspect feet/skin daily when neuropathy or vascular disease is present.
• Complete prescribed antibiotics and return urgently for severe pain, fever, rapidly spreading swelling, numbness, blisters or dark skin.
• Use safe injection, surgical and childbirth wound practices; ensure tetanus vaccination and infection-control procedures.
• After discharge, provide wound/rehabilitation appointments, mobility aids, mental-health support and clear return precautions.

Clinical scenarios

Common errors to avoid

• Calling it simple cellulitis because the skin looks mild early or because the patient is afebrile.
• Waiting for CT, MRI, culture results or a laboratory risk score before surgical consultation.
• Using antibiotics alone or closing a necrotic/infected wound.
• Failing to inspect the perineum, feet, pressure areas or surgical wounds.
• Giving large fluids without monitoring lungs/urine, or missing renal impairment and diabetes.

Revision questions

1. Why can necrotizing fasciitis look mild during the early phase?
2. List six red flags and five risk factors.
3. Why do antibiotics not replace surgical debridement?
4. What empirical antimicrobial coverage is required, and why may clindamycin be added?
5. Outline the immediate care of suspected Fournier’s gangrene.
6. Why should a low LRINEC score or normal imaging not end the assessment?

Key takeaways

References for further study

• CDC. Clinical Guidance for Type II Necrotizing Fasciitis.
• Infectious Diseases Society of America. Skin and Soft-Tissue Infection Guidelines.
• WHO Essential Medicines Committee. Antibiotics for necrotizing fasciitis.
• NHS. Necrotising fasciitis — warning signs and emergency care.
• Follow current Uganda Ministry of Health antimicrobial, sepsis, surgery and infection-control protocols.