From trauma to brain: Neoscytalidium dimidiatum as an emerging cause of cerebral phaeohyphomycosis: Case report and comprehensive literature review.

BACKGROUND

Neoscytalidium dimidiatum is a dematiaceous fungus typically causing superficial dermatomycosis. Invasive central nervous system (CNS) infections are rare, usually fatal, and primarily reported in immunocompromised patients. Pediatric CNS involvement is exceptionally uncommon.

CASE PRESENTATION: We report a 16-month-old previously healthy boy from Iran with a history of traumatic brain injury and cerebrospinal fluid shunt placement. Ten months post-injury, he presented with vomiting and swelling along the shunt tract. CSF analysis showed elevated protein and low glucose, and microscopy revealed dematiaceous septate hyphae with arthroconidia. Culture and ITS sequencing confirmed N. dimidiatum. Initial therapy with amphotericin B, caspofungin, and fluconazole was ineffective. Susceptibility-guided therapy, including intraventricular amphotericin B and systemic posaconazole followed by itraconazole, led to full clinical and radiological recovery.

RESULTS

The isolate showed low MIC to amphotericin B (0.25 μg/mL). Molecular confirmation via ITS sequencing was deposited in GenBank.

CONCLUSION

This case illustrates that N. dimidiatum can cause CNS infection in immunocompetent pediatric patients, particularly following traumatic inoculation or shunt placement. Early recognition, precise identification, and susceptibility-directed antifungal therapy, including intraventricular administration when indicated, are crucial for successful management of this otherwise highly fatal infection.