Primary Subcutaneous Candidiasis Presenting as a Chronic Eschar-Covered Ulcer: A Diagnostic Challenge in an Immunocompromised Host - A Case Report and Literature Review.

INTRODUCTION

Primary subcutaneous candidiasis is a rare, severe opportunistic infection. While Candida albicans is typically a commensal, it can become invasive in immunocompromised hosts, often mimicking other necrotic skin conditions.

CASE PRESENTATION: We describe an 83-year-old male with high-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia who developed a nonhealing eschar-covered ulcer on his left shin following a minor gardening injury. Despite multiple courses of broad-spectrum antibiotics, the lesion persisted. Initial superficial cultures were dismissed as colonization. However, multiple deep tissue biopsies and high-throughput internal transcribed spacer 2 sequencing confirmed invasive C. albicans. The patient was treated with intravenous Caspofungin for 3 weeks, leading to significant wound healing.

CONCLUSION

This case highlights the diagnostic challenge of "atypical" fungal ulcers. It underscores the importance of deep tissue biopsies and molecular sequencing in neutropenic patients to differentiate invasive pathogens from surface colonization and prevent systemic dissemination.