Anaerococcus vaginalis-Induced Acute Scrotal Abscess: A Case Report

Fournier's gangrene is a rapidly progressive necrotizing soft tissue infection of the perineum that is typically polymicrobial and is associated with substantial morbidity and mortality. Anaerococcus vaginalis is a rare anaerobic organism that has rarely been identified as a causative agent in necrotizing infections. To our knowledge, this organism has not previously been reported as the primary pathogen causing a scrotal abscess progressing to Fournier's gangrene. A 63-year-old male with a past medical history of alcoholic dementia presented to an urgent care facility with left hemiscrotal pain and swelling, which was identified as a hemiscrotal abscess. He underwent incision and drainage on site. Four days later, positive wound cultures prompted referral to the emergency department for further evaluation and management. Persistent pain and swelling prompted repeat imaging that revealed a 2.6-cm gas-containing subdermal collection within the left hemiscrotum concerning for necrotizing infection. Emergent operative exploration confirmed Fournier's gangrene, and debridement and excision of the scrotal wall cysts were performed. Intraoperative cultures grew A. vaginalis. The patient denied any sexual activity in the preceding 12 months. Empiric broad-spectrum antibiotics were initiated postoperatively and subsequently de-escalated to culture-directed oral therapy, which resulted in clinical improvement and discharge from the hospital. This case represents, to our knowledge, the first reported case of A. vaginalis as the primary pathogen in a scrotal abscess progressing to Fournier's gangrene. This report highlights the importance of early recognition, maintaining a broad differential for necrotizing infections, prompt surgical intervention, and culture-guided antibiotic management to optimize patient outcomes.