Treatment of Malassezia furfur Infections
For catheter-related bloodstream infections caused by Malassezia furfur, remove the intravascular catheter and discontinue intralipids, then treat with amphotericin B. 1
Catheter-Related Bloodstream Infections
For invasive M. furfur fungemia associated with intravascular catheters, the management approach is straightforward and critical:
- Remove the intravascular catheter immediately, especially for nontunneled catheter infections, as this is essential for infection control 1
- Discontinue intralipid infusions if the patient is receiving parenteral nutrition, as M. furfur has lipid-dependent growth requirements 1
- Initiate amphotericin B therapy as the antifungal agent of choice for catheter-related M. furfur fungemia 1
The evidence from the Infectious Diseases Society of America guidelines is clear that catheter removal combined with cessation of lipid infusions and amphotericin B treatment represents the standard of care for these invasive infections. 1
Cutaneous Malassezia Infections (Tinea Versicolor/Pityriasis Versicolor)
For skin infections caused by M. furfur, topical azole antifungals are highly effective:
- Ketoconazole 2% cream or shampoo is the most potent topical agent against M. furfur, with superior in vitro activity compared to other azoles 2, 3, 4
- Alternative topical azoles include bifonazole 1% cream, clotrimazole 1% cream, miconazole 2% cream, or flutrimazole 1-2% cream, all of which demonstrate efficacy in reducing M. furfur dermatitis 3
- For systemic therapy when indicated, oral ketoconazole (200 mg daily) or itraconazole achieve therapeutic levels in the keratin layer and can eradicate M. furfur 5, 4
The FDA-approved indication for ketoconazole 2% cream specifically includes treatment of tinea (pityriasis) versicolor caused by M. furfur. 2 In vitro susceptibility testing consistently shows ketoconazole has the lowest minimum inhibitory concentration (0.02-0.51 mg/L) against M. furfur compared to other azoles. 3, 4
Seborrheic Dermatitis Associated with Malassezia
When M. furfur contributes to seborrheic dermatitis:
- Use topical antifungal medications to reduce the yeast burden, as the therapeutic effect is postulated to result from reduction of Malassezia ovale 2
- Ketoconazole 2% shampoo or cream is effective for scalp and facial seborrheic dermatitis 2
- Combine with topical anti-inflammatory medications to reduce inflammation and pruritus associated with the condition 1
The mechanism involves ketoconazole impairing ergosterol synthesis in fungal cell membranes, which is vital for fungal survival. 2
Important Clinical Considerations
Common pitfall: Do not confuse M. furfur skin infections with other dermatoses that can mimic them, such as eczema, contact dermatitis, or seborrheic dermatitis from other causes. 1 Proper diagnosis requires clinical correlation and potentially culture on specialized lipid-supplemented media. 6
Recurrence prevention: M. furfur is part of the normal skin flora, so recurrence of cutaneous infections is common after treatment cessation. 6 Consider maintenance therapy or intermittent prophylactic treatment in patients with frequent recurrences. 7
Resistance concerns: While standardized susceptibility testing methods are lacking and clinical breakpoints are not established, treatment failures have been reported, likely due to premature discontinuation of therapy rather than true resistance. 7 Ensure adequate treatment duration for complete eradication.