Diagnosis and Treatment of Foot Fusarium Infection Confirmed by Molecular Identification: A Case Report and Literature Review

Fusarium spp. are opportunistic fungal pathogens, with an increasing incidence of infection observed in immunocompromised populations. Due to the non-specific clinical manifestations of cutaneous Fusarium infections, they are often misdiagnosed or overlooked. This article reports an 84-year-old man with a chronic post-traumatic foot lesion in whom histopathology was non-diagnostic, while the definitive diagnosis of Fusarium solani species complex (FSSC) was established by positive fungal culture from deep tissue biopsy followed by 18S rDNA/ITS sequencing. The patient's condition improved following individualized antifungal therapy. Combined with a literature review, we discuss the clinical characteristics, diagnostic and therapeutic strategies, and treatment challenges associated with FSSC skin infections. This case underscores the limitations of traditional fungal culture and highlights the necessity of molecular methods, such as 18S rDNA and Internal Transcribed Spacer (ITS) sequencing, for early and accurate diagnosis. Treatment should be guided by antifungal susceptibility testing and host immune status, with particular attention to the intrinsic resistance patterns of Fusarium species.