A Case of Invasive Fungal Infection Due to Scedosporium apiospermum in a Patient with Psoriasis

Abstract

Scedosporium apiospermum (S. apiospermum) is typically reported to be involved in superficial and subcutaneous fungal infections but overlooked in invasive infections, which is associated with a high mortality rate. It poses a diagnostic challenge due to its confusable characteristics to other hyaline hyphomycetes. Here, we reported a psoriasis patient with an invasive S. apiospermum infection. The patient presents an abscess at the intermuscular space of the left hip and an increased C-reactive protein level. Pus culture showed white-greyish, cottonlike colonies with aerial mycelium and terminal oval conidia, suggesting S. apiospermum. This rare fungus was rapidly confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and RNA sequencing. The patient was successfully treated with voriconazole with no recurrence of the abscesses despite delayed treatment. This is the first such case infection report from China that described an unusual case of intermuscular space abscesses due to S. apiospermum. This report highlights the possibility of fungal infections in deeper tissue, as well as the necessity of thorough evaluation and microbiological diagnosis for invasive infections, particularly in immunocompromised patients.

Keywords: Scedosporium; abscesses; fungal infections; fungi; infectious diseases; voriconazole.

Figure 1

Magnetic resonance imaging results. (A) Magnetic resonance imaging revealed the abscess in left psoas, gluteus maximus and iliac muscles (red arrow indicated), intermuscular encapsulated effusion, as well as enlarged lymph nodes in the left inguinal region. (B) Color Doppler ultrasound revealed a honeycomb, hypoechoic area in left Hip.

Figure 2

Morphological results of the pus culture. (A) Sabouraud dextrose agar medium showed the white-greyish, cottonlike colonies. (B and C) The thin, septate branching hyphae were observed on Columbia blood agar plate. (D) The lacto-phenol cotton blue staining showed the thick mycelium, along with the production of terminal oval conidia and a brush of cylindrical conidia (400× magnification).