What is the treatment for fungal Spontaneous Bacterial Peritonitis (SBP)?

Treatment of Spontaneous Fungal Peritonitis

Spontaneous fungal peritonitis should be treated with systemic antifungal therapy (fluconazole, amphotericin B, or echinocandins like caspofungin), though the evidence base is limited and prognosis remains poor despite treatment. 1

Clinical Context and Prognosis

• Spontaneous fungal peritonitis is a rare complication occurring in less than 5% of cases in cirrhotic patients with ascites 1
• Observational data consistently demonstrate a worse prognosis compared to bacterial SBP, with mortality rates ranging from 20-30% 1, 2
• The condition is less recognized and studied than bacterial SBP, resulting in limited high-quality evidence for treatment protocols 1

Diagnostic Approach

• Diagnosis follows the same principles as bacterial SBP: ascitic fluid neutrophil count >250/mm³ with positive fungal culture 1, 3
• Perform diagnostic paracentesis with inoculation of ascitic fluid into blood culture bottles before initiating treatment 1, 3
• Blood cultures should also be obtained, as fungal peritonitis can be associated with fungemia 1, 3
• The most common causative organisms are Candida species (particularly C. albicans, C. parapsilosis, and C. glabrata), though other yeasts and filamentous fungi can occur 2

Treatment Recommendations

Antifungal Therapy

Since no specific guidelines exist for spontaneous fungal peritonitis in cirrhosis, treatment must be extrapolated from fungal peritonitis management in other contexts:

• Fluconazole is the most commonly used agent for Candida peritonitis, with good ascitic fluid penetration 2
• Amphotericin B (conventional or lipid formulations) provides broader coverage including non-albicans Candida and filamentous fungi 2
• Echinocandins (caspofungin, micafungin, anidulafungin) represent newer options with potential advantages, though their role requires further study in this population 2
• Flucytosine can be used in combination with other agents, particularly amphotericin B 2
• Treatment should ideally be guided by fungal sensitivities once culture results are available 2

Critical Management Considerations

• Initiate antifungal therapy immediately upon diagnosis, following the same urgency principle as bacterial SBP 1, 3, 4
• Previous antibiotic therapy, particularly for bacterial peritonitis, is a major risk factor for fungal peritonitis due to fungal overgrowth and declining peritoneal defenses 2
• Consider fungal peritonitis in patients with SBP who fail to respond to appropriate antibacterial therapy after 48 hours 1, 4

Adjunctive Therapy

• Albumin administration (1.5 g/kg at diagnosis and 1 g/kg on day 3) should be considered, as it reduces hepatorenal syndrome and mortality in bacterial SBP 1, 3, 4
• While not specifically studied in fungal peritonitis, the pathophysiology of circulatory dysfunction is similar 1, 4

Monitoring Treatment Response

• Perform repeat paracentesis at 48 hours to assess treatment efficacy 1, 4
• Treatment success is indicated by a decrease in ascitic neutrophil count by at least 25% of pre-treatment value with clinical improvement 1, 4
• Failure to improve suggests resistant organisms, inadequate antifungal coverage, or secondary peritonitis requiring CT imaging and surgical evaluation 1, 4

Common Pitfalls

• Do not delay antifungal therapy waiting for culture confirmation if fungal peritonitis is suspected clinically 3, 4
• Distinguish from secondary peritonitis: suspect secondary peritonitis if multiple organisms are present, ascitic protein is high, neutrophil count is very elevated, or there is inadequate response to therapy 1
• Patients with suspected secondary peritonitis require prompt CT scanning and surgical consultation 1
• The high mortality associated with fungal peritonitis demands aggressive early treatment despite limited evidence 1, 2