- Primary (spontaneous) bacterial peritonitis – Occurs without an apparent source of contamination and is thought to be secondary to bacterial translocation across the bowel. It is most commonly found in patients with underlying cirrhosis and ascites, but may be found in patients with congestive heart failure, systemic lupus erythematosus, chronic viral hepatitis, or acute viral hepatitis. Presentation can be subtle, and up to 30% of patients may be asymptomatic. Fever is common, but presentation can be marked by altered mental status or abdominal pain in those with cirrhosis. This infection is often paucibacillary, and culture is not uncommonly negative. When an organism is identified, common organisms include Escherichia coli, streptococci, enterococci, and pneumococci.
- Secondary peritonitis – Results from the contamination of the peritoneum from spillage from an intraabdominal viscus, and results in gradually worsening abdominal pain as the parietal peritoneum becomes irritated. Pain, fever, and guarding are common presenting symptoms. Polymicrobial infections are common, including gram positive, gram negative, and anaerobes.
- Peritonitis secondary to ambulatory peritoneal dialysis (PD) – Presents with fever, diffuse abdominal pain, purulence at PD catheter site, guarding, and cloudy peritoneal fluid. Pathogens responsible are commonly skin flora such as Staphylococcus organisms.
K65.9 – Peritonitis, unspecified
48661000 – Peritonitis
Differential Diagnosis & Pitfalls
- Pancreatitis (acute, chronic)
- Colitis due to infectious (eg, Clostridioides difficile infection) and noninfectious (eg, inflammatory bowel disease [ulcerative colitis, Crohn disease]) causes
- Diabetic ketoacidosis
- Tuberculous peritonitis in patients with risk factors
- Fitz-Hugh-Curtis syndrome (gonococcal perihepatitis) as a complication of pelvic inflammatory disease
- Ectopic pregnancy
- Familial Mediterranean fever