Primary deep cutaneous candidiasis caused by Candida duobushaemulonii in a 68-year-old man: the first case report and literature review

Superficial candida infections of the skin are common, but deep cutaneous candidiasis, including secondary dissemination to the skin from systemic candidiasis, candidaemia or primary invasion due to skin defects such as trauma, is rare. These patients are usually immunosuppressed, but immunocompetent hosts can be affected as well. Candida albicans is the most common pathogen. However, non-albicans Candida species can cause deep skin invasion in rare circumstances. We report a case of deep cutaneous candidiasis caused by Candida duobushaemulonii in a 68-year-old man. Deep tissue invasion was confirmed by skin histopathology examination. The pathogen was initially identified as C. haemulonii using the VITEK^® 2 system for microbial identification, but was later determined to be C. duobushaemulonii based on sequencing of the internal transcribed spacer region of ribosomal DNA and D1/D2 region of 26S rDNA. The patient was successfully treated with amphotericin B, followed by fluconazole and surgical intervention. To the best of our knowledge, this is the first case of deep cutaneous infection by C. duobushaemulonii.