Diagnosis: Fungemia–Malassezia
• Malassezia furfur is a component of the normal skin microbiota in most individuals. Two major risk factors for infection with M. furfur are catheter-related fungemia in patients receiving total parenteral nutrition, which is high in lipids, and skin diseases, such as Pityrosporum folliculitis, pityriasis (tinea) versicolor, and atopic dermatitis.
• KOH preparations of skin infections with M. furfur demonstrate hyphae and spherical yeast cells and demonstrate a “spaghetti and meatball” appearance (see the figures).
• All Malassezia species require long-chain fatty acids for growth, with the exception of M. pachydermatis.
• Malassezia colonies appear cream colored to yellowish-brown and grow best at 30-35°C.
• Microscopically, Malassezia appears as phialides with small collarettes (Figure 2). Identification to the species level is best obtained by using molecular methods, such as sequencing.
• For skin infections, oral ketoconazole or itraconazole are commonly used for treatment. For systemic disease, amphotericin B is the drug of choice. Removing the catheter is critical for treating catheter-related infections.
