White Piedra: Clinical, Mycological, and Therapeutic Experience of Fourteen Cases

Abstract

White piedra (WP) is an asymptomatic superficial mycosis that affects the hair stems, forming whitish nodules caused by various species of the genus Trichosporon. Objective: To present a case series of WP of the head, its epidemiological data, as well as clinical, mycological, and therapeutic experience. Methods: We conducted a 12-year retrospective and observational study of WP cases tested by dermoscopy, mycological study, and the identification of species through morphology, biochemistry, and proteomics (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). The treatment was based on ketoco-nazole shampoo as well as keratolytics. Results: We included 14 cases of WP, all located in the head and 1 case with both head and scrotum affected. Nine cases (64.3%) presented in children aged < 15 years. The majority of the cases (13/14, 92.8%) were women. Two cases were associated with hyperkeratosis and intertrigo. Most patients had long hair and excessive moisture. In all cases hair nodules were observed and Trichosporon inkin>/(11/14, 78.6%) was usually isolated. Eleven cases (78.6%) were cured by administering 2% ketoconazole shampoo. Conclusion: WP was observed in school-age girls. The diagnosis was based on the observation of hair nodules and its main etiologic agent was T. inkin, with good response to treatment in most cases.