White piedra of the scalp caused by Trichosporon inkin: a case report with antifungal susceptibility testing and review of the literature

We report a case of white piedra of the scalp caused by Trichosporon inkin in a 38-year-old woman living in southern Brazil. Trichoscopic examination revealed whitish nodules involving the hair shafts. Blastoconidia clustered around the hair shaft were visualized by light microscopy with 10% KOH. The isolate was molecularly identified, and its antifungal susceptibility profile was defined following the M27-A3 protocol of the Clinical and Laboratory Standards Institute (CLSI), with itraconazole being the most effective antifungal agent, followed by ketoconazole. For treatment, topical medications were used, consisting of 1% itraconazole solution and 2% ketoconazole shampoo for 30days. The literature on cases of white piedra of the scalp caused by T. inkin, in addition to the in vitro antifungal susceptibility profile of this species, was reviewed.