Patients may present with scrotal swelling, abdominal pain, pruritus, crepitus, and fever.

The most important predisposing factors include diabetes mellitus and alcohol abuse. Other risk factors include localized trauma, indwelling catheters, HIV infection, and radiation or chemotherapy.

Common causal organisms are aerobic bacteria such as E. coli and Streptococcal species, and anaerobes such as B. fragilis.

Treatment includes intravenous antibiotics and immediate surgical debridement.

The perineum is divided into the urogenital triangle (bordered by the ischial rami laterally and pubis anteriorly) and anal triangle (bordered by the coccyx posteriorly and sacrotuberous ligaments laterally).

Disease arising from the anal triangle may spread along Colles’ fascia into the ischiorectal fossa and then into the buttocks and thighs.

Disease may also spread anteriorly via the Dartos fascia to involve the scrotum and penis.

Radiographs may demonstrate subcutaneous gas before crepitus is evident on physical exam (though the absence of radiographically apparent gas does not exclude the diagnosis).

Ultrasound may show scrotal wall thickening with edema, dirty shadowing from subcutaneous gas, and reactive hydroceles.

CT findings include thickening of the fascial planes, fluid collections, abscesses, and subcutaneous gas; CT may help differentiate Fournier gangrene from cellulitis and soft-tissue edema.