FUNGAL INFECTIONS OF SKIN AND SUBCUTANEOUS TISSUE (A BONIFAZ AND M PEREIRA, SECTION EDITORS) White Piedra, a Rare Superficial Mycosis: an Update Arturo Robles-Tenorio 1 & Kenia Yolanda Lepe-Moreno 1 & Jorge Mayorga-Rodríguez 2 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Purpose of Review White piedra (WP) is a rare superficial mycosis that has been poorly described in the literature. This review aims to summarize our current understanding of Trichosporon spp. infection and WP. Recent Findings Trichosporon spp. are part of the human skin microbiome. The mechanism of hair shaft infection and nodule ultrastructure has been identified. Trichoscopy is an important diagnostic tool. Besides the classical WP signs, atypical presen- tations and concomitant diseases have also been described. Combination of systemic and topical antifungals is more effective than topical therapy alone. Summary Most cases of WP have occurred in Latin America. High humidity, curly, and long hair are predisposing factors for scalp WP in females. Genital WP is more frequently reported in men. There is a paucity of studies describing the pathophysi- ology. Therapeutic recommendations are limited to small case series. Species identification is strongly encouraged for further basic and clinical research. Keywords White piedra . Trichosporon . Superficial mycosis . Hair mycosis Introduction The word “piedra” means “stone” in Spanish, and it is used to designate two rare clinical forms of superficial fungal infec- tions: black piedra (BP) and white piedra (WP), caused by and Piedra hortae and Trichosporon spp., respectively [1]. Etymologically, Trichosporon derives from the Greek words “trichos” and “sporon,” which mean “hair” and “spore.” The fungus is considered ubiquitous in nature but mostly prevails in tropical and subtropical regions. WP manifests as multiple white-to-yellow nodules that lie around terminal hairs, pre- dominantly involving the scalp and/or genital area. Arthrospores and blastospores can be observed with potassium hydroxide (KOH), forming irregularly interspaced concretions over the hair shafts [2•]. T. inkin, T. ovoides, and T. cutaneum are the most common causative species. The first line of therapy consists of topical antifungals and shaving the affected area. Systemic imidazoles may be prescribed to pre- vent recurrences and reinfection or when hair removal is re- fused by the patient [3••, 4]. Etiology WP is a superficial fungal infection typically caused by the Trichosporon genus [5]. Anecdotally, Rhodotorula rubra [6], Candida parapsilosis [7], and Cephalosporium acremonium [8] have also been documented in isolated case reports. Trichosporon spp. comprises different ubiquitous, oppor- tunistic, dimorphic basidiomycetous organisms known to be part of not only the human microbiome [9, 10••] but also the cause of superficial and invasive disease [11]. The genus was first described in 1865, and species were named together as Trichosporon beigelii. Later, modern microbiology and mo- lecular biology techniques facilitated the identification of 50 species, from which approximately 16 have a clinical rele- vance [12, 13]. T. inkin, T. cutaneum, and T. ovoides constitute This article is part of the Topical Collection on Fungal Infections of Skin and Subcutaneous Tissue * Arturo Robles-Tenorio arturo.robten@gmail.com 1 Instituto Dermatológico de Jalisco “Dr. José Barba Rubio” (IDJ), Av. Federalismo Norte 3102, Atemajac del Valle, Zapopan, Jalisco, Mexico 2 Centro de Referencia en Micología, IDJ, Av. Federalismo Norte 3102, Atemajac del Valle, Zapopan, Jalisco, Mexico Current Fungal Infection Reports https://doi.org/10.1007/s12281-020-00389-0