Fournier's Gangrene Etiology and Pathophysiology

Microbiology

• Fournier's gangrene is typically a polymicrobial infection involving both aerobic and anaerobic bacteria, with common aerobic organisms including Streptococcus species, Staphylococcus species, and Escherichia coli 1, 2, 3
• Anaerobic organisms are also frequently involved, contributing to the rapid tissue destruction 3

Pathophysiology

• The disease process begins with a localized infection that allows entry of commensal bacteria into the perineum, leading to inflammatory response and obliterative endarteritis with thrombosis of surrounding vessels 2, 3
• Vascular compromise causes tissue ischemia, promoting further anaerobic bacterial proliferation 2, 3
• Infection can extend cranially to the abdominal wall and caudally to the legs via superficial perineal fascia 2, 4

Risk Factors

• Diabetes mellitus is a major predisposing factor, and obesity is commonly associated 2, 3
• Conditions causing impaired host resistance and reduced cellular immunity, such as leukemia and other immunocompromising conditions, can also increase the risk 2, 3

Epidemiology

• Fournier's gangrene predominantly affects males with a male to female ratio of 42:1, and the mean age of presentation is 51 years 2, 4
• The overall incidence is approximately 1.6 cases per 100,000 males annually, and it accounts for less than 0.02% of all hospital admissions 2, 4
• Mortality rates vary widely, ranging from 7.5% to as high as 88% in some studies 2, 4

Treatment

• The American College of Surgeons recommends prompt recognition and immediate intervention with surgical debridement and broad-spectrum antibiotics to reduce the high associated mortality 5

Fournier's Gangrene Risk Factors and Pathogenesis

Anatomic Sources and Portals of Entry

• Anal sphincter involvement and fecal contamination can serve as infection sources, and urethral damage can provide bacterial entry, according to the World Journal of Emergency Surgery 6
• Perianal and perirectal abscesses, as well as urethral damage, are common anatomic sources of Fournier's gangrene, with the former representing the most common etiology at 45.8% of cases, and the latter providing a portal of entry for bacteria 6