What is the recommended treatment for chromoblastomycosis?

Treatment of Chromoblastomycosis

Itraconazole 200-400 mg daily for 6-12 months is the first-line treatment for chromoblastomycosis, with combination therapy using cryotherapy or terbinafine reserved for recalcitrant cases. 1, 2, 3, 4

First-Line Monotherapy

• Itraconazole 200-400 mg daily is the standard treatment, with cure rates ranging from 15-80% depending on disease severity and chronicity 2, 3, 4
• Treatment duration typically extends 6-12 months, though chronic fibrotic lesions may require up to 18-30 months 1, 4
• Monitor itraconazole serum levels after 2 weeks to ensure adequate drug exposure (target >1.0 μg/mL), as absorption varies significantly between patients 5
• The capsule formulation requires gastric acidity and should be taken with food; avoid concurrent proton pump inhibitors or use the solution formulation instead 5

Alternative Monotherapy Options

• Terbinafine shows excellent in vitro activity and can be used as monotherapy, though clinical data is more limited than for itraconazole 2, 4
• Posaconazole demonstrates the best in vitro MIC values among all antifungals tested and showed superior efficacy in animal models compared to itraconazole and voriconazole 2, 6
• Voriconazole has good in vitro activity but showed poor efficacy in animal models and should not be first-line 2, 6

Combination Therapy for Recalcitrant Disease

• Itraconazole 400 mg daily plus monthly liquid nitrogen cryotherapy achieves cure in 5-10 months for chronic fibrotic lesions that fail lower-dose monotherapy 1
• Itraconazole-terbinafine combination is widely recommended for severe or treatment-resistant cases 3, 4
• The terbinafine-voriconazole combination showed 100% synergy in vitro against Fonsecaea pedrosoi, though clinical data is lacking 2
• Itraconazole-caspofungin also demonstrated 100% synergy in vitro, but echinocandins alone have poor activity against chromoblastomycosis agents 2

Treatment Algorithm by Disease Severity

Mild to Moderate Disease (Early, Limited Lesions)

• Start with itraconazole 200 mg daily for 6-12 months 1, 4
• Monitor clinical response at 3 months; if inadequate, increase to 400 mg daily 1

Severe or Chronic Fibrotic Disease

• Itraconazole 400 mg daily plus monthly cryotherapy from treatment initiation 1
• Consider adding terbinafine if response remains inadequate after 3-6 months 3, 4

Recalcitrant Cases After Failed Monotherapy

• Switch to posaconazole or add terbinafine to existing itraconazole regimen 2, 3, 6
• Continue combination therapy until complete clinical and mycological cure 4

Monitoring and Treatment Endpoints

• Treatment endpoint is mycological cure, not just clinical resolution 4
• Perform repeat fungal cultures and histopathology to confirm eradication of muriform cells before discontinuing therapy 4
• Continue treatment for several months beyond clinical resolution to prevent relapse 1, 4
• Monitor hepatic enzymes before starting therapy, at 2 and 4 weeks, then every 3 months during prolonged treatment 7

Critical Pitfalls to Avoid

• Do not use fluconazole as it has poor activity against dematiaceous fungi causing chromoblastomycosis 2
• Do not use echinocandins as monotherapy despite some in vitro synergy data, as they lack adequate activity alone 2
• Do not stop treatment based solely on clinical improvement without confirming mycological cure, as relapse rates are high 1, 4
• Do not use itraconazole capsules in patients on proton pump inhibitors without switching to the solution formulation or monitoring drug levels closely 5