Makindo Medical Notes

Related Subjects: |Cellulitis |Pyoderma gangrenosum |Pemphigus Vulgaris |Toxic Epidermal Necrolysis |Stevens-Johnson Syndrome |Necrotising fasciitis |Gas Gangrene (Clostridium perfringens) |Purpura Fulminans |Anatomy of Skin

⚠️ Fournier’s gangrene is a rapidly progressing, life-threatening necrotizing fasciitis of the perineum. Testes and penis are often spared due to their separate blood supply from the external iliac arteries. This is a surgical emergency with high mortality — early recognition and aggressive management are critical.

📖 About

• Necrotizing fasciitis of scrotum, perineum, and lower abdominal wall.
• Polymicrobial in most cases (aerobic + anaerobic organisms).
• Rapid onset, systemic toxicity, and tissue destruction.

🦠 Aetiology (Common Pathogens)

• E. coli (most common aerobic gram-negative).
• Bacteroides (common anaerobe).
• Group A streptococci (S. pyogenes).
• Staphylococcus aureus (including MRSA).
• Klebsiella, Pseudomonas, other coliforms.
• Anaerobes including Clostridium species (occasionally, with gas gangrene).

⚡ Risk Factors

• Diabetes mellitus (up to 80% of cases).
• Alcoholism, cirrhosis, or chronic liver disease.
• Immunosuppression (HIV, steroids, chemotherapy, SLE).
• Crohn’s disease, perianal abscess, urinary tract infections.
• Obesity and poor hygiene.

🩺 Clinical Presentation

• Severe genital/perineal pain (often disproportionate to exam findings).
• Rapidly spreading erythema, blistering, oedema.
• Cyanosis, dusky skin, necrosis.
• Crepitus (gas in tissue) → anaerobic infection.
• Foul-smelling discharge, wet gangrene.
• Systemic toxicity: fever, tachycardia, hypotension, shock.

⚠️ Complications

• Septic shock and multiorgan failure.
• DKA in diabetics.
• DIC and severe coagulopathy.
• Acute kidney injury.
• Extensive tissue loss → reconstructive surgery required.

🔍 Investigations

• Bloods: FBC (↑ WCC), CRP (↑), U&E (renal impairment).
• Blood cultures: identify causative organisms.
• Imaging: CT/MRI to define disease extent and gas in soft tissues (but do not delay surgery).
• Bedside: clinical suspicion remains most important; do not wait for labs before acting.

💊 Management

• 🚨 Immediate surgical debridement — do not delay.
• Repeat debridement often required.
• Early broad-spectrum IV antibiotics:
  • Piperacillin–Tazobactam 4.5 g IV tds
  • If penicillin allergic: Clindamycin 600 mg qds IV + Gentamicin IV OD (clindamycin inhibits toxin production).
• Supportive care: IV fluids, ICU, organ support as needed.
• Adjunct: hyperbaric oxygen (controversial, sometimes used to suppress anaerobes and improve wound healing).

💡 Pearls for exams & practice:
- Fournier’s = polymicrobial necrotising fasciitis of the perineum.
- High mortality (20–40%); delays in debridement increase risk.
- Always suspect in diabetics with rapidly spreading perineal pain and systemic sepsis.
- Management requires a “triple approach”: 🚨 surgery + 💊 antibiotics + 🩺 critical care support.