Fournier's gangrene is a form of necrotising fasciitis that affects the perineum. Whilst rare, it is a urological emergency with a mortality rate of 20-40%.
Pathophysiology
- Can be monomicrobial or polymicrobial infection
- Causative organisms include:
- Group A streptococcus
- Clostridium perfringens
- Escherichia coli
Anatomical Spread
There is a predictable pathway for spread based on scrotal anatomy. Anatomic barriers include:
- Dartos fascia of penis and scrotum
- Colles fascia of perineum
- Scarpa fascia of anterior abdominal wall
The testes and epididymis are commonly not affected by the fasciitis.
Risk Factors
Metabolic
Diabetes mellitus
Lifestyle
Excess alcohol, smoking, poor nutrition
Medications
Steroid use, immunosuppression
Other
Haematological malignancies, recent trauma
Clinical Features
Early Stage
- Severe perineal/scrotal pain (disproportionate to signs)
- Erythema
- Swelling
- Pyrexia
- Often non-specific until significant deterioration
Late Stage
- Crepitus
- Skin necrosis
- Haemorrhagic bullae
- Sensory loss of overlying skin
- Rapid deterioration to sepsis
Differential Diagnosis
In the setting of acute scrotal pain:
- Epididymo-orchitis
- Testicular torsion
- Testicular trauma
- Scrotal cellulitis/abscess
Investigations
Diagnosis is largely clinical. Any suspected cases should be taken for immediate surgical exploration.
Essential Tests
- Routine bloods (FBC, U&E, CRP)
- Blood cultures
Imaging
Useful if diagnosis unclear, to determine extent of disease or detect underlying cause:
| Modality |
Findings |
| Plain radiograph |
- Radiolucent soft-tissue gas in scrotum/perineum
- Subcutaneous emphysema may extend to inguinal regions, abdominal wall, thighs
|
| Ultrasound |
- Thickened scrotal wall
- Echogenic gas foci in scrotum (pathognomonic)
- Testes and epididymides spared
- Peritesticular fluid
|
| CT |
- Soft tissue stranding, fascial thickening
- Soft tissue gas
- Demarcates extent of disease
- May reveal cause (e.g., perianal abscess, fistula)
|
Management
Definitive Management
Urgent surgical debridement - The earlier performed, the better the outcomes.
Surgical debridement usually encompasses partial or total orchiectomy, depending on extent, with wound left open.
Medical Management
- Broad-spectrum antibiotics initially (tailor to culture sensitivities later)
- Aggressive fluid resuscitation
- Transfer to high-dependency setting
Follow-up Care
- Often requires further surgical debridement
- Secondary closure with skin grafts may be needed
- Post-operative outcomes vary by disease extent
Prognosis
Factors Affecting Mortality
- Time to surgical intervention
- Extent of tissue involvement
- Presence of sepsis/shock
- Underlying comorbidities
- Age and immune status