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.
🩺 OSCE Vignette: Fournier’s Gangrene
A 65-year-old man with poorly controlled type 2 diabetes presents to the Emergency Department with severe perineal pain for 24 hours.
On examination, he is febrile (39.2 °C), tachycardic (HR 125), and hypotensive (BP 85/50).
Inspection shows erythema, swelling, and dusky discolouration of the scrotum with a foul-smelling discharge.
Crepitus is felt on palpation.
❓ Candidate Tasks
- What is the most likely diagnosis?
- List three risk factors for this condition.
- Outline your immediate management.
✅ Examiner’s Guide / Mark Scheme
- Diagnosis: Fournier’s gangrene (necrotising fasciitis of the perineum).
- Risk factors: Diabetes mellitus, obesity, alcoholism, immunosuppression, perianal/urinary infection.
- Immediate management:
- 🚨 Urgent surgical referral for debridement (do not delay).
- 💊 Start broad-spectrum IV antibiotics (e.g., Piperacillin-Tazobactam; if allergic → Clindamycin + Gentamicin).
- 💉 Aggressive IV fluid resuscitation & sepsis protocol (Sepsis 6).
- 🔬 Blood cultures, baseline bloods (FBC, U&E, CRP), consider imaging but don’t delay surgery.
- 🩺 ICU support for monitoring, vasopressors if shock persists.
💡 Exam Pearl: Fournier’s gangrene is a surgical emergency.
The key to passing is to recognise it early and emphasise “urgent debridement” + broad antibiotics + sepsis care.
Never focus solely on antibiotics — surgery is life-saving.
