Pseudallescheria boydii (Allescheria boydii, Petriellidium boydii)

Epidemiology

• pseudallescheria boydii is the sexual state & Scedosporium apiospermum is the asexual state of the same fungus
• associated with fungal infection in debilitated patients
• not as common a pathogen as Aspergillus

Pathology

• organisms indistinguishable from Aspergillus on histology
• acute angle branching with slender mycelia
• necrosis with a predominantly neutriphil infiltate
• abscess formation
• mild granulomatous response with macrophages & multinucleated giant cells
• particular tropism for blood vessel
• vascular organs, brain, & thyroid involved in disseminated disease

Clinical manifestations

• similar to aspergillosis

Laboratory

• Pseudallescheria boydii IgG in serum Differential diagonisis:
• Aspergillus

Management

• voriconazole or posaconazole
• resistant to antifungals effective against Aspergillus

Notes

• Scedosporium apiospermum may be asexual state of Pseudallescheria boydii

More general terms

• pseudallescheria (allescheria, petriellidium)

More specific terms

• Scedosporium apiospermum

Additional terms

• pseudallescheriosis