Fournier Gangrene

Fournier gangrene

Fournier gangrene is a fulminant form of necrotising fasciitis involving the perineum, external genitalia and often the lower anterior abdominal wall. It is a surgical emergency: infection spreads rapidly along fascial planes, causes local tissue necrosis and systemic sepsis, and carries substantial mortality unless there is prompt resuscitation, broad antimicrobial therapy and early surgical source control (NICE NG141; NG253; RCEM).

Epidemiology and predisposing factors

• Most commonly affects older men (male:female ratios reported up to ~40:1) but can occur at any age and in women or children.
• The single most common risk factor is diabetes mellitus.
• Other important predispositions include:
• Immunosuppression (HIV, corticosteroids, chemotherapy).
• Malignancy (particularly anorectal/urogenital).
• Liver cirrhosis, chronic alcohol misuse, malnutrition.
• Peripheral vascular disease and poor tissue perfusion.
• Obesity and intravenous drug use.
• Recent perineal/urogenital procedures or local infection.
• SGLT2 inhibitor therapy has been associated with rare cases of Fournier gangrene; if suspected, stop the drug immediately and manage as an emergency (MHRA).

Pathophysiology and microbiology

• The infection is typically polymicrobial. Synergy between aerobic and anaerobic organisms produces toxins, local vascular thrombosis and rapid fascial necrosis; gas production from anaerobes may cause palpable crepitus.
• Common isolates include mixed Gram-negative bacilli (Enterobacterales), Gram-positive cocci (streptococci, staphylococci), anaerobes (Bacteroides, Clostridium spp.) and occasionally specific pathogens (e.g., Vibrio vulnificus with marine exposures).