Fournier's gangrene is an acute, rapidly progressive, and potentially fatal necrotising fasciitis of the external genitalia, perineum, or perianal region. It is a urological emergency — survival depends on early recognition and aggressive surgical debridement.
Definition and History
First described in 1764 by Baurienne, the condition is named after Professor Jean-Alfred Fournier (1832–1914), a Parisian venereologist who in 1883 presented a case of perineal gangrene in an otherwise healthy young man.
Relevant Anatomy
Understanding the fascial planes explains both how the infection spreads and which structures it spares.
Layers superficial to deep (above the inguinal ligament):
- Skin.
- Camper's fascia — fat-containing tissue of variable thickness carrying the superficial vessels to the skin.
- Scarpa's fascia — continuous with Colles' fascia (superficial perineal fascia) in the perineum and Dartos fascia in the penis and scrotum.
Superficial perineal space: Colles' fascia attaches to the pubic arch and the base of the perineal membrane (the inferior fascia of the urogenital diaphragm); together they define the superficial perineal space, which contains the membranous urethra, bulbar urethra, and bulbourethral glands and lies adjacent to the anterior anal wall and ischiorectal fossae. Infection of the male urethra, bulbourethral glands, perineal structures, or rectum can drain into this space and extend into the scrotum or up the anterior abdominal wall to the level of the clavicles.
What is involved vs spared: Fournier's involves the superficial and deep fascia (Camper's, Scarpa's/Dartos/Colles') and skin, but often spares the deep muscle and, variably, the overlying skin. The corpora, urethra, testes, and cord structures are usually not involved — the scrotal contents are wrapped by their own fascial layers, distinct from the Dartos:
- External spermatic fascia (most superficial; continuous with the external oblique aponeurosis at the superficial inguinal ring).
- Internal spermatic fascia (continuous with the transversalis fascia).
- Buck's fascia covers the corpora cavernosa and anterior urethra and fuses to the tunica albuginea deep in the pelvis.
These layers are not breached by a superficial perineal-space infection, limiting the depth of destruction.
Routes of spread (and their limits):
- Posteriorly along Dartos → Colles' fascia, but the attachment of Colles' fascia to the perineal body stops it at the anal margin — infection is limited posteriorly by Colles' fascia.
- Up the anterior abdominal wall through the potential space between Scarpa's fascia and the deep fascia (external oblique); superiorly Scarpa's and Camper's coalesce and attach to the clavicles — infection is limited superiorly by the clavicles.
Pathogenesis and Risk Factors
Infection most commonly arises from the skin, urethra, or rectal region and usually begins as cellulitis adjacent to the portal of entry. Risk factors:
- Diabetes mellitus.
- Local trauma.
- Paraphimosis.
- Urethral stricture (often STI-related, causing periurethral urine extravasation).
- Urethrocutaneous fistula.
- Perirectal or perianal infection.
- Instrumentation.
- Surgery such as circumcision or herniorrhaphy.
Diagnosis and Evaluation
- History and exam — early on the area is swollen, erythematous, and tender as the infection reaches the deep fascia; discharge is absent early. Pain is prominent and systemic toxicity is marked. Distinguishing necrotising fasciitis from cellulitis is difficult because the initial signs (pain, oedema, erythema) are non-specific — but marked systemic toxicity and pain out of proportion to the exam should alert the clinician.
- Labs — wound cultures generally yield multiple organisms, reflecting anaerobic-aerobic synergy.
- Imaging — CT pelvis shows signs of necrotising fasciitis and subcutaneous gas.
Management
This is a urological emergency. The three essential interventions are early recognition, aggressive surgical debridement, and broad-spectrum antibiotics.
- Antibiotics — broad-spectrum cover with a β-lactam plus β-lactamase inhibitor, e.g. piperacillin-tazobactam.
- Resuscitation — IV hydration in preparation for debridement.
- Surgery — immediate debridement of skin and the involved Dartos/Scarpa's/Colles' fascia is essential. Make an extensive incision through skin and subcutaneous tissue beyond the involved area until normal fascia is reached; excise necrotic fat and fascia and leave the wound open. (Prep widely with antiseptic — up to the clavicles and down the thighs.)
- Spared structures — the external, cremasteric, and internal spermatic fasciae are spared (embryologically distinct, with their own blood and nerve supplies). Orchiectomy is almost never required, because the testes have an independent blood supply from the compromised scrotal circulation.
- Re-look — a second procedure at 24–48 hours is indicated if there is any doubt about the adequacy of the initial debridement.
- Adjunctive procedures (include in pre-surgical consent) — suprapubic urinary diversion if urethral trauma or extravasation is suspected, and colostomy for colonic or rectal perforation.