Case report: subcutaneous Exophiala xenobiotica infection successfully treated with a combined medical and surgical approach

Abstract

Exophiala xenobiotica is a black yeast from the Exophiala genus. Literature suggests it has consistently been underdiagnosed in recent years, because of poor microbiological identification techniques and the discovery of multiple new species within the genus. Exophiala xenobiotica most commonly causes subcutaneous infections. It often thrives in damp places, and places where there are aromatic compounds. This report describes a multi-comorbid patient including previous basal cell carcinoma and prostate cancer who developed this infection. An 88-year-old caucasian man presented to the orthopaedic clinic with a lump on the dorsum of his right wrist, he was given a provisional diagnosis of a ganglion cyst. The lesion had been there for two years and had steadily increased in size. The patient had no pain or systemic symptoms and was not prescribed any immunosuppressive medication. After the yeast was isolated, he was prescribed an eight-week course of itraconazole, with surgical excision of the lesion two weeks into the course. The procedure was a success, and the lesion showed no signs of recurrence at the six-week follow up. This case report adds to the literature supporting a combined surgical and medical approach for the treatment of subcutaneous Exophiala xenobiotica infections.