Indwelling catheters and immune disorders are risk factors for systemic Malassezia infection
March 08 2019
Malassezia spp. (formerly Pityrosporum) are commensal yeasts that typically cause skin infections, but preterm infants and immunocompromised patients are at risk of life-threatening systemic involvement, often via indwelling medical devices. While the prevalence of systemic infections is low, mortality is high — partly because diagnosis (and therefore treatment) is often delayed. Clinical course is often indolent, with non-specific symptoms such as fever of unknown origin. In addition, laboratory culture requires non-standard media containing lipids, and susceptibility testing is not routinely available.
Dr Ana Filipa Pedrosa and colleagues in Porto (Portugal) have published a series of 3 unrelated cases of Malassezia bloodstream infection with an accompanying literature review. All 3 patients had a central venous catheter
- 2yo female in paediatric ward for fever of unknown origin. Glucocorticoid therapy and autoimmune disease (reduced IL-12). On broad-spectrum antibiotics. Received fluconazole and liposomal AmB, survived but contracted pityriasis versicolor 3 years later.
- 68yo female in ICU for systemic inflammatory response syndrome. HIV+ on HAART, with chemotherapy for oral carcinoma. On fluconazole prophylaxis. Received liposomal AmB but died after 15 days.
- 60yo male in ICU for acute respiratory distress syndrome. HIV+ on HAART, with chemotherapy for Hodgkin disease. On fluconazole prophylaxis. Received liposomal AmB but died after 3 days.
Read the paper: Pedrosa et al (2018) J Dermatol 45(11):1278-82
What can I do?
- NICU clinicians: be aware that infections are more likely when infants are receiving lipid infusions (on TPN)
- Blood cultures are the gold standard for diagnosis, and should be supplemented with lipids (e.g. palmitic acid, sterile olive oil) and incubated for up to 2 weeks. Identification to species level requires molecular tests or MALDI-ToF, and is not generally required for clinical management
- If a central venous catheter is involved, remove it promptly
- For patients who develop this infection while under fluconazole prophylaxis, use amphotericin B as first-line treatment but be aware that susceptibility profiles are not well characterised for this group of yeasts