Case report Dermatophytosis caused by Nannizzia nana C. Porras-Lo ´ pez a,c,1 , E. Martı ´nez-Herrera b,c,d,1 , M.G. Frı ´as-De-Leo ´n b,d , G. Moreno-Coutin ˜o c,e , M. del Rocı ´o Reyes-Montes f , R. Arenas c,e,g , J.L. Gonza ´ lez-Cespo ´n g , C. Rodrı ´guez-Cerdeira c,d,g,h, * a Facultad de Ciencias Quı´micas y Farmacia, Universidad de San Carlos de Guatemala, Guatemala b Unidad de Investigacio ´n, Hospital Regional de Alta Especialidad de Ixtapaluca, Mexico c Psychodermatology task force of the Ibero-Latin American College of Dermatology (CILAD), Buenos Aires, Argentina d European Women’s Dermatologic and Venereologic Society (EWDVS), Tui, Spain e Seccio ´n de Micologı´a, Hospital General ‘‘Dr. Manuel Gea Gonza ´lez’’ Ciudad de Me ´xico, Mexico f Departamento de Microbiologı´a, Universidad Nacional Auto ´noma de Me ´xico (UNAM), Mexico, Mexico g Efficiency, Quality, and Costs in Health Services Research Group (EFISALUD), Health Research Institute, SERGAS-UVIGO, Vigo, Spain h Dermatology Department, Hospital do Meixoeiro and University of Vigo, 36200 Vigo, Spain Introduction Dermatophyte taxonomy has undergone notable changes since 1950 when the genera Trichophyton, Microsporum, and Epidermo- phyton were described by de Hoog et al. [1]. Currently, owing to the taxonomic classification based on polyphasic studies, the following nine genera are recognized: Trichophyton, Epidermophyton, Nan- nizzia, Lophophyton, Paraphyton, Microsporum, Arthroderma, Cte- nomyces and Guarromyces, with more than 50 species [1]. In this new classification, the anthropophilic dermatophytes (and some zoophilic species that are commonly associated with human infections) are belong to the genera Trichophyton, Epidermophyton, and Microsporum, but the geophilic species and those zoophilic species that are only rarely encountered in human disease are distributed amongst Arthroderma, Nannizzia, Lophophyton, and Paraphyton [1,2]. However, in clinical practice, the first classifica- tion that includes only three genera is still commonly used, or empirical treatments are administered without reaching the microbiological identification of the pathogen. This has led to the epidemiology of the newly described dermatophytes to be poorly known or biased, particularly in the case of fungi that rarely infect humans, such as those belonging to the genus Nannizzia, previously considered as the genus Microsporum [1–4],constituted by thirteen species: Nannizzia fulva, Nannizzia corniculata, Nanniz- zia >incurvata, Nannizzia gypsea, Nannizzia lorica, Nannizzia aenigmatica, Nannizzia duboisii, Nannizzia nana, Nannizzia poly- morpha, Nannizzia persicolor, Nannizzia praecox, Nannizzia graese- Journal de Mycologie Me ´ dicale xxx (xxxx) xxx A R T I C L E I N F O Article history: Received 16 April 2020 Accepted 22 September 2020 Available online xxx Keywords: Dermatophytes Nannizzia nana Epidemiology Diagnostic techniques Treatment A B S T R A C T Purpose. – In this paper, we reported three distinct cases of tinea, including tenia ungulum, tenia pedis, and tenia cruris caused by the infection of Nannizzia nana in the immunocompetent patients who were also the residents of Guatemala. Dermatophytes were identified phenotypically and genotypically. Thereafter, DNA was extracted from the fungal isolates and a fragment of the ITS1-5.8S-ITS2 region was amplified and sequenced. The direct visual examination revealed the presence of fungal hyphae and arthroconidia. These characteristic morphological features resembled with the general features of the species, Nannizzia nana. Furthermore, nucleotide sequences that were amplified from the fungal isolates, confirmed the species identification. Thereafter, all the patients were treated with Terbinafine (250 mg) through oral route for two weeks, except the patient with onychomycosis, who received the same treatment but for an extended period of three months. All the patients showed complete recovery from dermatophytosis. This study contributes to a better understanding of the epidemiology of human infections that are caused by dermatophytes, often misdiagnosed. Dermatophytes are currently less known but are now being more frequently identified due to the improvements in the diagnostic techniques.  C 2020 Elsevier Masson SAS. All rights reserved. * Corresponding author at: Dermatology Department, Hospital do Meixoeiro and University of Vigo, 36200 Vigo, Spain. E-mail address: carmencerdeira33@gmail.com (C. Rodrı ´guez-Cerdeira). 1 Carlos Porras-Lo ´ pez and Erick Martı ´nez-Herrera, these authors contributed equally so they must be considered co-first authors. This article is part of the Topical Collection on Fungal Infections of Skin and Subcutaneous Tissue. G Model MYCMED-101047; No. of Pages 4 Available online at ScienceDirect www.sciencedirect.com https://doi.org/10.1016/j.mycmed.2020.101047 1156-5233/  C 2020 Elsevier Masson SAS. All rights reserved. Please cite this article as: C. Porras-Lo ´ pez, E. Martı ´nez-Herrera, M.G. Frı ´as-De-Leo ´n et al., Dermatophytosis caused by Nannizzia nana, Journal De Mycologie Me ´ dicale, https://doi.org/10.1016/j.mycmed.2020.101047