Spontaneous Bacterial Peritonitis due to Actinomyces Mimicking a Perforation of the Proximal Jejunum

Area of Science:

• Microbiology
• Infectious Diseases
• Surgical Pathology

Background:

• Pelvic-abdominal actinomycosis is a rare, chronic infection caused by Actinomyces species, often presenting with abscesses.
• Its diverse clinical and radiological features can lead to misdiagnosis.
• Peritonitis without preceding abscesses is exceptionally rare.

Observation:

• A 42-year-old female with an intrauterine contraceptive device presented with spontaneous pelvic-abdominal peritonitis and pneumoperitoneum.
• Initial laparotomy revealed significant pus but no clear cause, mimicking proximal jejunal perforation.
• The intrauterine device was removed, and Actinomyces turicensis was identified via cultivation.

Findings:

• Actinomyces turicensis was identified as the causative agent of acute peritonitis.
• The patient successfully responded to penicillin therapy.
• The case highlights a rare presentation of actinomycosis without abscess formation.

Implications:

• Actinomyces should be considered in cases of primary bacterial peritonitis or unexplained lower abdominal pain, particularly in patients with intrauterine devices.
• This case underscores the importance of considering rare pathogens in the differential diagnosis of acute abdominal conditions.
• Prompt identification and appropriate antibiotic treatment are key to successful management of actinomycosis.