Multiple subcutaneous cysts due to Exophiala spinifera in an immunocompetent patient

Here we report a case of a 55-year-old Indian male presenting with multiple subcutaneous cysts, which developed from painful nodules at the dorsal right wrist joint. Subsequently a painful nodule appeared on the left knee joint. Cytological examination of the knee swelling revealed a suppurative inflammatory lesion consisting of neutrophils, lymphocytes, multinucleated giant cells and few fungal elements, without involvement of the overlying skin. Exophiala spinifera was cultured (CBS 125607) and its identity was confirmed by sequencing of the internal transcribed spacer (ITS rDNA). The cysts were excised surgically, without need of additional antifungal therapy. There was no relapse during one-year follow-up and the patient was cured successfully. In vitro antifungal susceptibility testing showed that posaconazole (0.063 μg/ml) and itraconazole (0.125 μg/ml) had the highest and caspofungin (4 μg/ml) and anidulafungin (2 μg/ml) the lowest activity against this isolate. However, their clinical effectiveness in the treatment of E. spinifera infections remains to be evaluated. In this case report, we have also compiled cases of human E. spinifera mycoses which have been reported so far.