Fournier gangrene is a necrotising fasciitis of the perineum. It is a true urological emergency due to the high mortality rate but fortunately the condition is rare.
Fournier gangrene is typically seen in diabetic men aged 50-70 but is rarely seen in women. Other than age, predisposing factors include:
- perineal/scrotal pain, swelling, redness
- crepitus from soft tissue gas (up to 65%)
- systemically unwell
- fever and leukocytosis
The source of infection can usually be identified, most commonly anorectal (such as from a fistula or perianal abscess) and less commonly genitourinary or perineal trauma. Sometimes the cause is not found.
The infection is usually polymicrobial. The commonest organisms cultured are E.coli, Klebsiella, Proteus, Staph, Strep.
It begins as a cellulitis that causes an endarteritis and then necrotising infection that spreads through the fascial planes. The organisms often produce gas, thus causing a gas gangrene.
The diagnosis is usually clinical. The role of imaging includes:
- diagnosis not established
- determine extent of disease
- detect underlying cause
- thickened scrotal wall
- echogenic gas foci in scrotum pathognomonic - seen as dirty shadowing
- testes and epididymi spared (due to their separate blood supply)
- soft tissue stranding, fascial thickening
- soft tissue gas
- the extent of disease can be assessed prior to surgery
- a cause of infection may be apparent (e.g. perianal abscess, fistula)
Treatment and prognosis
Management options include:
- immediate radical surgical debridement of necrotic tissue
- intravenous antibiotics
- hyperbaric oxygen therapy has been used
- testes replaced into remaining scrotum or covered by skin graft (once infection settled)
Often carries a poor prognosis with up to 33% mortality.
History and etymology
It was first described by French venereologist Jean Alfred Fournier in 1883 who noted a fulminating gangrenous infection of male genitalia in young healthy males without an obvious cause.
The differential in the setting of acute scrotal pain includes: