Overview
- Necrotising fasciitis is a rapidly spreading, destructive, and invasive infection of the skin and subcutaneous tissues. It results in necrosis of subcutaneous tissues and the overlying skin.
- Most Common Organism: β-haemolytic streptococci (Streptococcus pyogenes) → Polymicrobial.
Common Sites
- Lower Extremities (Most Common)
- Fournier’s Gangrene: Perineal area
- Meleney’s Gangrene: Abdominal wall
Pathogenesis
- Acute Inflammatory Infiltrate
- Extensive Necrosis
- Oedema
- Thrombosis of Microvasculature
Clinical Presentation
- Oedematous, painful, and very tender area.
- Skin turns dusky blue and black due to progressive thrombosis and necrosis.
- Fever, severe toxicity.
- The affected area may develop bullae and progress to overt cutaneous gangrene.
- Septic shock leading to hypovolemia, cardiovascular collapse, and renal failure.
The infection spreads contiguously but can occasionally produce skip lesions that later coalesce.
Diagnosis
- Clinical Diagnosis based on symptoms and physical examination.
Treatment
- ICU Admission
- Oxygen Therapy
- IV Antibiotic Therapy: High-Dose Penicillin G, Broad-Spectrum Antibiotics: Such as 3rd generation cephalosporins & metronidazole.
- Surgical Excision: Devitalized tissue should be removed generously, extending beyond the area of induration.
This process is repeated daily, as necrosis tends to spread beyond the edges of the excised wound.
