A Rare Case of White Piedra Caused by Candida orthopsilosis

A Rare Case of White Piedra Caused by Candida orthopsilosis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Rare Case of White Piedra Caused by Candida orthopsilosis Azam Moslemi, Armaghan Kazeminejad, Maryam Salimi, Sabah Mayahi, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5819410/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 15 Oct, 2025 Read the published version in BMC Infectious Diseases → Version 1 posted 9 You are reading this latest preprint version Abstract Objectives White piedra (WP) is a fungal infection that affects hair shafts, resulting in the formation of soft nodules that can be white, gray, or brown. While it was initially believed to be caused by Trichosporon beigelii , genetic analysis has reclassified Trichosporon inkin , T. ovoides , and T. cutaneum , as the primary causative agents of WP. In this report, we present a rare documented case of WP caused by Candida orthopsilosis , as a member of Candida parapsilosis complex, occurring without presence of Trichosporon in a temperate region in northern Iran. Case presentation : A 3-year-old girl visited a dermatology clinic with complaints of hair knots in the occipital area, particularly around the ears, that were difficult to remove. These symptoms have persisted for two months. The patient has no history of gym classes or kindergarten attendance and was not taking any specific medications. No other areas of her body were affected, and none of her family members reported experiencing any symptoms. Fungal isolates were identified using PCR-RFLP and confirmed by sequencing. Antifungal susceptibility testing of the isolates was conducted based on CLSI M27-S3 guidelines. Conclusions We suggest that C. orthopsilosis can cause WP independently of Trichosporon species, particularly in temperate regions. Future studies should establish a clear relationship between the yeast responsible for WP and its geographic location. This case could increase awareness among dermatologists and laboratory physicians, emphasizing that the growth of Candida species should not be dismissed as contaminant. Candida orthopsilosis White piedra Candida parapsilosis complex Trichosporon beigelii Figures Figure 1 Background Superficial fungal infections are skin diseases that affect hair, nails, and skin, and they are prevalent worldwide, with a prevalence rate of 20–25%( 1 ). The three most common superficial fungal infections are dermatophytosis, pityriasis versicolor, and candidiasis ( 2 ). White piedra (WP) is a relatively rare superficial fungal infection caused by Trichosporon species that occurs on hair shafts, leading to the development of soft nodules that can be white, gray, or brown. Risk factors for developing WP include having long hair, using hair bands or accessories, and maintaining damp hair ( 3 ). Trichosporon species are similar to Candida species in their ability to adhere to form biofilms( 4 ). Human-to-human transmission can occur in unsanitary and overcrowded living conditions or through shared use of hair-styling products ( 5 ). This rare chronic superficial infection primarily observed in tropical and temperate climate regions. WP is frequently misdiagnosed and often mistaken for conditions such as pediculosis ( 6 ). The genus Trichosporon has been undergoing taxonomic reclassification. Currently, approximately 50 species have been identified and categorized into four distinct clades, with 16 species are recognized as human pathogens. The primary etiological agents responsible for WP include Trichosporon inkin , Trichosporon ovoides , and Trichosporon cutaneum , while Trichosporon asahii and Trichosporon loubieri have been implicated in rare cases ( 7 ). Now, Trichosporon ovoides is well recognized as the main causative agent of WP on the scalp, while T. in kin, T. asahii , and T. mucoides are associated with WP in pubic hair. Some research suggest that Candida can also cause WP, rather than just Trichosporon species. So far, two cases of WP caused by Candida parapsilosis have been reported one of which was co- isolated with T. inkin ( 8 ). In this report, we present a rare documented case of WP caused by Candida orthopsilosis , as a member of Candida parapsilosis complex, occurring without presence of Trichosporon in a temperate region in northern Iran. Case presentation A 3-year-old girl visited the dermatology clinic with complaints of hair knots in the occipital area, particularly around the ears, which are difficult to remove. These symptoms have persisted for two months. She has no history of attending gym classes or kindergarten, nor is taking any specific medications. No other areas of her body are affected, and none of the family members are experiencing any symptoms. The patient experiences significant sweating and itching on the scalp. The examination revealed a normal-appearing scalp with long hair, exhibiting no signs of thinning. The hair shafts displayed visible, well-defined white to beige nodules that were irregularly spaced and not easily movable along the shafts (Fig. 1 a, b). Laboratory examination Direct microscopic examination using a 10% potassium hydroxide wet mount revealed sleeve-like formations surrounding the hair shafts (Fig. 1 c), which featured spore-like structures composed of hyphae and blastoconidia. The infected hairs were inoculated on Sabouraud dextrose agar (Merck, Germany) (with the addition of chloramphenicol) and incubated at 30°C. Cream‑colored colonies developed after five days (Fig. 1 d). In order to extract fungal genomic DNA, some of the infected hair strands were crushed using liquid nitrogen in a sterile ceramic mortar and suspended them in 400 µl of lysis buffer (10 mM Tris, 1mM EDTA (pH 8), 1% SDS, 100mM NaCl, 300µl phenol-chloroform (1:1)). This mixture shaken for 5 minutes and then centrifuged at 10000 rpm for 10 min, the supernatant was transferred to new tube and equal volume of chloroform was added, mixed and centrifuged at 10000 rpm for 10 min .The supernatant was transferred to new tube and an equal volume of cool isopropanol along with 30 µl of sodium acetate (3 M) was added. This mixture was centrifuged at 10000 rpm for 10 min. Decant supernatant and added 300 µl of 70% ethanol alcohol and centrifuged at 10000 rpm for 7 min. The resulting DNA pellet was dried and re-suspended in 50 µl of doubled distilled water (DDW), then stored at -20˚C until use. The genomic DNA of the fungal isolate was amplified using a fungal universal primer pair: forward primer ITS1(5’-TAAGTAGGTGTTCCTGCG G-3’) and reverse primer ITS4 (5’-TCGTCCGCTTATTCATATGC-3’). The PCR reaction required 12.5 µL of the master mix and 1 µL of each primer. A total of 2 µL of DNA and 8.5 µl of DDW was transferred to a microtube, bringing the final volume of the PCR reaction to 25 µL. The thermal cycling conditions included an initial denaturation at 95°C for 5 minutes, followed by 35 cycles of denaturation at 94°C for 30 seconds, annealing at 56°C for 1 minutes, and extension at 72°C for 1 minutes. A final extension step was conducted at 72°C for 7 minutes ( 9 ). The molecular weight of the PCR product is 510bp. Following the PCR process, Restriction Fragment Length Polymorphism (RFLP) analysis was performed using the restriction enzymes Msp I (Fermentas, Vilnius, Lithuania) to identify common Candida species. For this digestion, 10 µL of PCR product was combined with 1.5 µL of digestion buffer, 5 units of Msp I enzyme, and DDW to a final volume of 15. This mixture was incubated at 37°C for 2 hours. The resulting restriction fragments were visualized using 2% agarose gel electrophoresis. The Msp I enzyme was unable to digest the target product, which consisted of the C. parapsilosis complex ( 9 ). for accurate identification the ITS PCR amplicon was sequenced. The obtained sequence was aligned with the GenBank database ( https://blast.ncbi.nlm.nih.gov/Blast.cgi ), revealing a similarity that identified as Candida orthopsilosis . The sequence was submitted to GenBank and received accession number PQ721052. The antifungal susceptibility test (AFST) of the isolate was conducted according to the Clinical and Laboratories Standards Institute protocol (CLSI M27-S3). The minimum inhibitory concentration (MIC) values were determined as follow: itraconazole at 0.25µg/ml, voriconazole at 0.015 µg/ml, amphotericin B at 1 µg/ml, fluconazole at 0.5 µg/ml, miconazole at 0.5 µg/ml, clotrimazole at 0.015 µg/ml. The minimum effective concentration (MEC) values for caspofungin and anidulafungin were found to be 1 µg/ml and 0.015 µg/ml, respectively. The patient was received prescribed treatment and advised to return for a follow up after two weeks. After this period, all the hair nodules were successfully cleared with a combination of antifungal therapies, including 1%of clotrimazole suspension and 2% ketoconazole shampoo. There was no relapse during the two months follow-up. Basic immunological evaluations, including quantitative profiling of immune cells, revealed no abnormalities. However, qualitative functional assessment of immune cells was not performed, which could have provided deeper insights into potential predisposing factors. Discussion and Conclusions While Trichosporon species remain the primary agents of WP, recent reports and our current case suggest that the diagnostic criteria should be expanded to include Candida species that display identical clinical and microscopic features. WP predominantly affects the scalp hair of female preschool-aged children (2–6 years), particularly in the occipital region, as noted in the case presented here ( 10 ). In recent decades, the incidence of infections caused by C. parapsilosis complex which includes C. parapsilosis senso stricto, C. orthopsilosis and C. metapsilosis has significantly increased. The increase in infections is mainly attributed to the growing number of immunocompromised patients and the more frequent use of indwelling medical devices. The C. parapsilosis complex is one of the primary causes of fungal infections related to medical devices due to its strong ability to form biofilms associated with these devices. The source of infection can be the skin or other colonized body sites, with Candida species, particularly the C. parapsilosis complex, commonly found as skin colonizers( 11 ). Multiple studies have investigated the prevalence of C. orthopsilosis and C. metapsilosis in human infections that were previously classified only as C. parapsilosis ( 12 ). However, C. orthopsilosis , may still pose a significant health risk and has been linked to two outbreaks in hospitals located in Texas ( 13 ) and Brazil ( 14 ). The three species of C. parapsilosis complex has ability to form biofilms ( 15 ). In contrast Some reports indicate that C. orthopsilosis and C. metapsilosis do not have the ability to form biofilms ( 16 ). However, the biofilms of C. orthopsilosis and C. metapsilosis may be smaller in size ( 17 ). Additionally, a scanning electron microscope analysis of human hair surface revealed that isolates of the C. parapsilosis complex, which exhibited distinct phenotypes, demonstrated varying adherence and biofilm formation patterns on keratinized natural substrates ( 18 ). It is important to note that while biofilm activity was not evaluated in the current case, this aspect remains speculative and was not the focus of this report. In the present study, we reported a superficial infection caused by C. orthopsilosis , with the AFS test isolate showing good activity against antifungals. The medications clotrimazole and ketoconazole yielded satisfactory results. Candida orthopsilosis is characterized by ellipsoid to sub-globose budding blastoconidia, measuring 2–5 × 3–7 µm, along with some larger elongated forms( 19 ).This recently identified species within the C. parapsilosis complex, has been associated to bloodstream infections in neonates, transplant recipients, and patients receiving parenteral nutrition. Candida orthopsilosis is susceptible to various antifungal agents, including amphotericin B, fluconazole, itraconazole, and echinocandins ( 20 ). In the present study, we reported a superficial infection with C. orthopsilosis agent, which the AFS test isolate showing good activity against antifungals. The medications with clotrimazole and ketoconazole produced satisfactory results. In conclusion, Future studies should aim to establish a clear relationship between the yeast responsible for WP and geographic location. We propose that C . orthopsilosis may contribute to WP alongside Trichosporon species, particularly in temperate regions. This case serves to raise awareness among dermatologists and laboratory specialist that the growth of Candida species should not be dismissed as merely a contaminant. While our diagnostic approach confirmed C. orthopsilosis infection, cellular activity profiling was beyond the scope of this clinical case study. Further laboratory research is needed to investigate this aspect. One limitation of this study is that, although we performed quantitative immune profiling (including T cell and immunoglobulin levels), was did not conduct any functional (qualitative) immune assays. Functional evaluations of the immune response could have provided more accurate insights into potential underlying immunodeficiencies or predisposing factors contributing to the infection. Further studies are needed to assess these aspects in greater detail. Abbreviations WP White piedra SDA Sabouraud dextrose agar AFST Antifungal susceptibility test PCR Polymerase Chain Reaction RFLP Restriction fragment length polymorphism CLSI Clinical and Laboratories Standards Institute MIC Minimum inhibitory concentration Declarations Acknowledgements We acknowledge the active participation of all patients, health workers, and laboratory personnel at the burn hospitals who made this study feasible. Authors' contributions T.S., A.M., and A.K. conceived and designed the study and final approval of the version to be published. T.S. and A.K. were involved in clinical data collection. A.M., M.S. S.M. and A.M. provided the microbiological report and wrote the draft. All authors have read, critically revised, and approved the final manuscript. Funding No funding. Data availability Sequence data were deposited into the GenBank database () under accession number PQ721052at the following URL: https://www.ncbi.nlm.nih.gov/nuccore/PQ721052 Ethics approval and consent to participate The Ethics Committee of Mazandaran University of Medical Sciences, Sari, Iran approved his report (IR.MAZUMS.REC.1403.421), and informed consent was obtained from the legal guardian to participate. Consent for publication The authors declare that written informed consent has been obtained from the individual for the publication of any potentially identifiable images or data included in this article. Availability of data All data generated or analyzed during this study are included in this published article. Competing interests All authors have no conflict of interest to declare to relation on this work. References Havlickova B, Czaika VA, Friedrich M. Epidemiological trends in skin mycoses worldwide. Mycoses. 2008;51:2-15. Kurç MA, Kaya AD, Erfan G, Albayrak Ş. Distribution and antifungal susceptibility profiles of candida species isolated from dermatomycosis patients. Journal of Health Sciences and Medicine.7(3):290-5. Guerrero‐Ponce AE, Araiza J, Tirado‐Sánchez A, Bonifaz A. Review Article White Piedra: Review of 131 cases. Mycoses. 2024;67(1):e13668. Mehta V, Nayyar C, Gulati N, Singla N, Rai S, Chandar J. A Comprehensive Review of Trichosporon spp.: An Invasive and Emerging Fungus. Cureus. 2021;13(8):e17345. Robles-Tenorio A, Lepe-Moreno KY, Mayorga-Rodríguez J. White piedra, a rare superficial mycosis: an update. Current Fungal Infection Reports. 2020;14:197-202. de Carvalho Sugai JB, Di Rito NP, Lourenço A, Mamoni RL, Falleiros ACDM, de Moraes Alves CAX, et al. White piedra on Pediatric Scalp: A Case Report. IDCases. 2024:e02002. Colombo AL, Padovan ACB, Chaves GM. Current knowledge of Trichosporon spp. and Trichosporonosis. Clinical microbiology reviews. 2011;24(4):682-700. Sharma RK, Verma GK, Verma S, Thakur S, Gupta A. A rare case of white piedra caused by Candida parapsilosis in the Sub-Himalayan Region of North India. International Journal of Trichology. 2019;11(2):82-5. Moslemi A, Shokohi T, Salimi M, Faeli L, Davoodi L, Kashi Z, et al. Clinic-mycological spectrum of Candida infection in diabetic foot ulcers in a tertiary care hospital. Current Medical Mycology. 2023;9(4):9. Coutinho ASS. Scalp white Piedra: case report of a pediatric patient Anglya Samara Silva Leite Coutinho, Orlando Oliveira de Morais, Ciro Martins Gomes Carolina Bruno Bruno, Carmélia Matos Santiago Reis 2. Egyptian Dermatology Online Journal. 2011;7(1):8. Lotfali E, Kordbacheh P, Mirhendi H, Zaini F, Ghajari A, Mohammadi R, et al. Antifungal susceptibility analysis of clinical isolates of Candida parapsilosis in Iran. Iranian journal of public health. 2016;45(3):322. Riccombeni A, Vidanes G, Proux-Wéra E, Wolfe KH, Butler G. Sequence and analysis of the genome of the pathogenic yeast Candida orthopsilosis. PLoS One. 2012;7(4):e35750. Lin D, Wu L-C, Rinaldi MG, Lehmann PF. Three distinct genotypes within Candida parapsilosis from clinical sources. Journal of Clinical Microbiology. 1995;33(7):1815-21. Zancope-Oliveira R, James MJ, Derossi A, Sampaio J, Muniz M, Li R, et al. Strain characterization of Candida parapsilosis fungemia by molecular typing methods. European Journal of Clinical Microbiology and Infectious Diseases. 2000;19:514-20. Lattif AA, Mukherjee PK, Chandra J, Swindell K, Lockhart SR, Diekema DJ, et al. Characterization of biofilms formed by Candida parapsilosis, C. metapsilosis, and C. orthopsilosis. International Journal of Medical Microbiology. 2010;300(4):265-70. De Toro M, Torres M, Maite R, Aznar J. Characterization of Candida parapsilosis complex isolates. Clinical Microbiology and Infection. 2011;17(3):418-24. Melo AS, Bizerra FC, Freymüller E, Arthington-Skaggs BA, Colombo AL. Biofilm production and evaluation of antifungal susceptibility amongst clinical Candida spp. isolates, including strains of the Candida parapsilosis complex. Medical mycology. 2011;49(3):253-62. Oliveira MT, Specian AFL, Andrade CG, França EJ, Furlaneto-Maia L, Furlaneto MC. Interaction of Candida parapsilosis isolates with human hair and nail surfaces revealed by scanning electron microscopy analysis. Micron. 2010;41(6):604-8. Larone D. Medically important fungi: a guide to identification. 2011. Khullar G, Vignesh P, Lau YL, Rudramurthy SM, Rawat A, De D, et al. Chronic mucocutaneous candidiasis. The Journal of Allergy and Clinical Immunology: In Practice. 2017;5(4):1119-21. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 15 Oct, 2025 Read the published version in BMC Infectious Diseases → Version 1 posted Editorial decision: Accepted 19 Sep, 2025 Reviews received at journal 13 May, 2025 Reviews received at journal 13 May, 2025 Editor assigned by journal 05 May, 2025 Reviewers agreed at journal 28 Apr, 2025 Reviewers agreed at journal 28 Apr, 2025 Reviewers invited by journal 22 Apr, 2025 Submission checks completed at journal 20 Apr, 2025 First submitted to journal 16 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5819410","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":446315530,"identity":"07f7441e-9dd1-47a6-a16a-84f020fb3703","order_by":0,"name":"Azam Moslemi","email":"","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Azam","middleName":"","lastName":"Moslemi","suffix":""},{"id":446315532,"identity":"7e4c7f93-db7c-4250-bad5-49db76d31dc1","order_by":1,"name":"Armaghan Kazeminejad","email":"","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Armaghan","middleName":"","lastName":"Kazeminejad","suffix":""},{"id":446315539,"identity":"d888d844-edc3-417f-8b00-ce41a22ae0b3","order_by":2,"name":"Maryam Salimi","email":"","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Maryam","middleName":"","lastName":"Salimi","suffix":""},{"id":446315544,"identity":"0712edf2-7475-4560-9c45-7abe2bb541a6","order_by":3,"name":"Sabah Mayahi","email":"","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Sabah","middleName":"","lastName":"Mayahi","suffix":""},{"id":446315558,"identity":"8cc780be-4f76-4878-9088-d3c560c0bc39","order_by":4,"name":"Anahita Mohsenpour","email":"","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Anahita","middleName":"","lastName":"Mohsenpour","suffix":""},{"id":446315560,"identity":"8bcee020-3f07-43b7-b14a-a126408ee858","order_by":5,"name":"Tahereh Shokohi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABB0lEQVRIiWNgGAWjYDACCQZmBsYGCSCLB8Q9IAcmHxCjhQeqxRhMJhDWwgDXktgAovBpkZ/dfNjg4w4LBnv2swcfV1TcSZ8fdvgh0BY7Od0G7FoM7hxLTpx5BugwnrxkwzNnnuVuvJ1mANSSbGx2AIcWiRzjw7xtIL/kmEk2th3O3Tg7AaTlQOI2HFrkZ8C08L8x/9n473C64ez0D3i1MNzIMU4Ga5HIMWNsbDicIC+dg98WgxtpyYYz2yR4eG68MZZsOHbYcIN0TsGBBAPcfpGfkXxY4mNbnRx7f47hx4aaw/Lys9M3f/hQYSeHSwsM8CDsBas0wK8czd4GUlSPglEwCkbBSAAAcGdhSJ3KI+IAAAAASUVORK5CYII=","orcid":"","institution":"Mazandaran University of Medical Sciences","correspondingAuthor":true,"prefix":"","firstName":"Tahereh","middleName":"","lastName":"Shokohi","suffix":""}],"badges":[],"createdAt":"2025-01-13 11:23:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5819410/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5819410/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12879-025-11787-5","type":"published","date":"2025-10-15T15:56:52+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":81521339,"identity":"7f83694d-7e29-48ac-ae66-386317704856","added_by":"auto","created_at":"2025-04-28 08:06:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":651712,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea, b \u003c/strong\u003eA white to beige nodules in the occipital area, particularly around the ears.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ec, \u003c/strong\u003eNodules around of\u003cstrong\u003e \u003c/strong\u003ehair shaft in direct microscopy in 10% potassium hydroxide mount at microscopy in(x40).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ed,\u003c/strong\u003e Cream‑colored colonies in Sabouraud dextrose agar supplemented with chloramphenicol.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5819410/v1/814247341263a46daa4e7834.png"},{"id":93956141,"identity":"74e7686b-34df-4da1-99cd-a1e1d6e979bd","added_by":"auto","created_at":"2025-10-20 16:11:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1097784,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5819410/v1/190e6494-0560-4da9-ac9c-4d018c8e576b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Rare Case of White Piedra Caused by Candida orthopsilosis","fulltext":[{"header":"Background","content":"\u003cp\u003eSuperficial fungal infections are skin diseases that affect hair, nails, and skin, and they are prevalent worldwide, with a prevalence rate of 20\u0026ndash;25%(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). The three most common superficial fungal infections are dermatophytosis, pityriasis versicolor, and candidiasis (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). White piedra (WP) is a relatively rare superficial fungal infection caused by \u003cem\u003eTrichosporon\u003c/em\u003e species that occurs on hair shafts, leading to the development of soft nodules that can be white, gray, or brown. Risk factors for developing WP include having long hair, using hair bands or accessories, and maintaining damp hair (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). \u003cem\u003eTrichosporon\u003c/em\u003e species are similar to \u003cem\u003eCandida\u003c/em\u003e species in their ability to adhere to form biofilms(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Human-to-human transmission can occur in unsanitary and overcrowded living conditions or through shared use of hair-styling products (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). This rare chronic superficial infection primarily observed in tropical and temperate climate regions. WP is frequently misdiagnosed and often mistaken for conditions such as pediculosis (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The genus \u003cem\u003eTrichosporon\u003c/em\u003e has been undergoing taxonomic reclassification. Currently, approximately 50 species have been identified and categorized into four distinct clades, with 16 species are recognized as human pathogens. The primary etiological agents responsible for WP include \u003cem\u003eTrichosporon inkin\u003c/em\u003e, \u003cem\u003eTrichosporon ovoides\u003c/em\u003e, and \u003cem\u003eTrichosporon cutaneum\u003c/em\u003e, while \u003cem\u003eTrichosporon asahii\u003c/em\u003e and \u003cem\u003eTrichosporon loubieri\u003c/em\u003e have been implicated in rare cases (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Now, \u003cem\u003eTrichosporon ovoides\u003c/em\u003e is well recognized as the main causative agent of WP on the scalp, while \u003cem\u003eT. in\u003c/em\u003ekin, \u003cem\u003eT. asahii\u003c/em\u003e, and \u003cem\u003eT. mucoides\u003c/em\u003e are associated with WP in pubic hair. Some research suggest that \u003cem\u003eCandida\u003c/em\u003e can also cause WP, rather than just \u003cem\u003eTrichosporon\u003c/em\u003e species. So far, two cases of WP caused by \u003cem\u003eCandida parapsilosis\u003c/em\u003e have been reported one of which was co- isolated with \u003cem\u003eT.\u003c/em\u003e inkin (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). In this report, we present a rare documented case of WP caused by \u003cem\u003eCandida orthopsilosis\u003c/em\u003e, as a member of \u003cem\u003eCandida parapsilosis\u003c/em\u003e complex, occurring without presence of \u003cem\u003eTrichosporon\u003c/em\u003e in a temperate region in northern Iran.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 3-year-old girl visited the dermatology clinic with complaints of hair knots in the occipital area, particularly around the ears, which are difficult to remove. These symptoms have persisted for two months. She has no history of attending gym classes or kindergarten, nor is taking any specific medications. No other areas of her body are affected, and none of the family members are experiencing any symptoms.\u003c/p\u003e \u003cp\u003eThe patient experiences significant sweating and itching on the scalp. The examination revealed a normal-appearing scalp with long hair, exhibiting no signs of thinning. The hair shafts displayed visible, well-defined white to beige nodules that were irregularly spaced and not easily movable along the shafts (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea, b).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eLaboratory examination\u003c/h2\u003e \u003cp\u003eDirect microscopic examination using a 10% potassium hydroxide wet mount revealed sleeve-like formations surrounding the hair shafts (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec), which featured spore-like structures composed of hyphae and blastoconidia. The infected hairs were inoculated on Sabouraud dextrose agar (Merck, Germany) (with the addition of chloramphenicol) and incubated at 30\u0026deg;C. Cream‑colored colonies developed after five days (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). In order to extract fungal genomic DNA, some of the infected hair strands were crushed using liquid nitrogen in a sterile ceramic mortar and suspended them in 400 \u0026micro;l of lysis buffer (10 mM Tris, 1mM EDTA (pH 8), 1% SDS, 100mM NaCl, 300\u0026micro;l phenol-chloroform (1:1)). This mixture shaken for 5 minutes and then centrifuged at 10000 rpm for 10 min, the supernatant was transferred to new tube and equal volume of chloroform was added, mixed and centrifuged at 10000 rpm for 10 min .The supernatant was transferred to new tube and an equal volume of cool isopropanol along with 30 \u0026micro;l of sodium acetate (3 M) was added. This mixture was centrifuged at 10000 rpm for 10 min. Decant supernatant and added 300 \u0026micro;l of 70% ethanol alcohol and centrifuged at 10000 rpm for 7 min. The resulting DNA pellet was dried and re-suspended in 50 \u0026micro;l of doubled distilled water (DDW), then stored at -20˚C until use.\u003c/p\u003e \u003cp\u003eThe genomic DNA of the fungal isolate was amplified using a fungal universal primer pair: forward primer ITS1(5\u0026rsquo;-TAAGTAGGTGTTCCTGCG G-3\u0026rsquo;) and reverse primer ITS4 (5\u0026rsquo;-TCGTCCGCTTATTCATATGC-3\u0026rsquo;). The PCR reaction required 12.5 \u0026micro;L of the master mix and 1 \u0026micro;L of each primer. A total of 2 \u0026micro;L of DNA and 8.5 \u0026micro;l of DDW was transferred to a microtube, bringing the final volume of the PCR reaction to 25 \u0026micro;L. The thermal cycling conditions included an initial denaturation at 95\u0026deg;C for 5 minutes, followed by 35 cycles of denaturation at 94\u0026deg;C for 30 seconds, annealing at 56\u0026deg;C for 1 minutes, and extension at 72\u0026deg;C for 1 minutes. A final extension step was conducted at 72\u0026deg;C for 7 minutes (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). The molecular weight of the PCR product is 510bp.\u003c/p\u003e \u003cp\u003eFollowing the PCR process, Restriction Fragment Length Polymorphism (RFLP) analysis was performed using the restriction enzymes \u003cem\u003eMsp\u003c/em\u003eI (Fermentas, Vilnius, Lithuania) to identify common \u003cem\u003eCandida\u003c/em\u003e species. For this digestion, 10 \u0026micro;L of PCR product was combined with 1.5 \u0026micro;L of digestion buffer, 5 units of \u003cem\u003eMsp\u003c/em\u003eI enzyme, and DDW to a final volume of 15. This mixture was incubated at 37\u0026deg;C for 2 hours. The resulting restriction fragments were visualized using 2% agarose gel electrophoresis. The \u003cem\u003eMsp\u003c/em\u003eI enzyme was unable to digest the target product, which consisted of the \u003cem\u003eC. parapsilosis\u003c/em\u003e complex (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). for accurate identification the ITS PCR amplicon was sequenced. The obtained sequence was aligned with the GenBank database (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://blast.ncbi.nlm.nih.gov/Blast.cgi\u003c/span\u003e\u003cspan address=\"https://blast.ncbi.nlm.nih.gov/Blast.cgi\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e), revealing a similarity that identified as \u003cem\u003eCandida orthopsilosis\u003c/em\u003e. The sequence was submitted to GenBank and received accession number PQ721052.\u003c/p\u003e \u003cp\u003eThe antifungal susceptibility test (AFST) of the isolate was conducted according to the Clinical and Laboratories Standards Institute protocol (CLSI M27-S3). The minimum inhibitory concentration (MIC) values were determined as follow: itraconazole at 0.25\u0026micro;g/ml, voriconazole at 0.015 \u0026micro;g/ml, amphotericin B at 1 \u0026micro;g/ml, fluconazole at 0.5 \u0026micro;g/ml, miconazole at 0.5 \u0026micro;g/ml, clotrimazole at 0.015 \u0026micro;g/ml. The minimum effective concentration (MEC) values for caspofungin and anidulafungin were found to be 1 \u0026micro;g/ml and 0.015 \u0026micro;g/ml, respectively. The patient was received prescribed treatment and advised to return for a follow up after two weeks. After this period, all the hair nodules were successfully cleared with a combination of antifungal therapies, including 1%of clotrimazole suspension and 2% ketoconazole shampoo. There was no relapse during the two months follow-up. Basic immunological evaluations, including quantitative profiling of immune cells, revealed no abnormalities. However, qualitative functional assessment of immune cells was not performed, which could have provided deeper insights into potential predisposing factors.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion and Conclusions","content":"\u003cp\u003eWhile \u003cem\u003eTrichosporon\u003c/em\u003e species remain the primary agents of WP, recent reports and our current case suggest that the diagnostic criteria should be expanded to include \u003cem\u003eCandida\u003c/em\u003e species that display identical clinical and microscopic features. WP predominantly affects the scalp hair of female preschool-aged children (2\u0026ndash;6 years), particularly in the occipital region, as noted in the case presented here (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn recent decades, the incidence of infections caused by \u003cem\u003eC. parapsilosis\u003c/em\u003e complex which includes \u003cem\u003eC. parapsilosis\u003c/em\u003e senso stricto, \u003cem\u003eC. orthopsilosis\u003c/em\u003e and \u003cem\u003eC. metapsilosis\u003c/em\u003e has significantly increased. The increase in infections is mainly attributed to the growing number of immunocompromised patients and the more frequent use of indwelling medical devices. The \u003cem\u003eC. parapsilosis\u003c/em\u003e complex is one of the primary causes of fungal infections related to medical devices due to its strong ability to form biofilms associated with these devices. The source of infection can be the skin or other colonized body sites, with \u003cem\u003eCandida\u003c/em\u003e species, particularly the \u003cem\u003eC. parapsilosis\u003c/em\u003e complex, commonly found as skin colonizers(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMultiple studies have investigated the prevalence of \u003cem\u003eC. orthopsilosis\u003c/em\u003e and \u003cem\u003eC. metapsilosis\u003c/em\u003e in human infections that were previously classified only as \u003cem\u003eC. parapsilosis\u003c/em\u003e (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). However, \u003cem\u003eC. orthopsilosis\u003c/em\u003e, may still pose a significant health risk and has been linked to two outbreaks in hospitals located in Texas (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e) and Brazil (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe three species of \u003cem\u003eC. parapsilosis\u003c/em\u003e complex has ability to form biofilms (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). In contrast Some reports indicate that \u003cem\u003eC. orthopsilosis\u003c/em\u003e and \u003cem\u003eC. metapsilosis\u003c/em\u003e do not have the ability to form biofilms (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). However, the biofilms of \u003cem\u003eC. orthopsilosis\u003c/em\u003e and \u003cem\u003eC. metapsilosis\u003c/em\u003e may be smaller in size (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Additionally, a scanning electron microscope analysis of human hair surface revealed that isolates of the \u003cem\u003eC. parapsilosis\u003c/em\u003e complex, which exhibited distinct phenotypes, demonstrated varying adherence and biofilm formation patterns on keratinized natural substrates (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). It is important to note that while biofilm activity was not evaluated in the current case, this aspect remains speculative and was not the focus of this report.\u003c/p\u003e \u003cp\u003eIn the present study, we reported a superficial infection caused by \u003cem\u003eC. orthopsilosis\u003c/em\u003e, with the AFS test isolate showing good activity against antifungals. The medications clotrimazole and ketoconazole yielded satisfactory results.\u003c/p\u003e \u003cp\u003e \u003cem\u003eCandida orthopsilosis\u003c/em\u003e is characterized by ellipsoid to sub-globose budding blastoconidia, measuring 2\u0026ndash;5 \u0026times; 3\u0026ndash;7 \u0026micro;m, along with some larger elongated forms(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).This recently identified species within the \u003cem\u003eC. parapsilosis\u003c/em\u003e complex, has been associated to bloodstream infections in neonates, transplant recipients, and patients receiving parenteral nutrition. \u003cem\u003eCandida orthopsilosis\u003c/em\u003e is susceptible to various antifungal agents, including amphotericin B, fluconazole, itraconazole, and echinocandins (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the present study, we reported a superficial infection with \u003cem\u003eC. orthopsilosis\u003c/em\u003e agent, which the AFS test isolate showing good activity against antifungals. The medications with clotrimazole and ketoconazole produced satisfactory results.\u003c/p\u003e \u003cp\u003eIn conclusion, Future studies should aim to establish a clear relationship between the yeast responsible for WP and geographic location. We propose that \u003cem\u003eC\u003c/em\u003e. \u003cem\u003eorthopsilosis\u003c/em\u003e may contribute to WP alongside \u003cem\u003eTrichosporon\u003c/em\u003e species, particularly in temperate regions. This case serves to raise awareness among dermatologists and laboratory specialist that the growth of \u003cem\u003eCandida\u003c/em\u003e species should not be dismissed as merely a contaminant.\u003c/p\u003e \u003cp\u003eWhile our diagnostic approach confirmed \u003cem\u003eC. orthopsilosis\u003c/em\u003e infection, cellular activity profiling was beyond the scope of this clinical case study. Further laboratory research is needed to investigate this aspect.\u003c/p\u003e \u003cp\u003eOne limitation of this study is that, although we performed quantitative immune profiling (including T cell and immunoglobulin levels), was did not conduct any functional (qualitative) immune assays. Functional evaluations of the immune response could have provided more accurate insights into potential underlying immunodeficiencies or predisposing factors contributing to the infection. Further studies are needed to assess these aspects in greater detail.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eWP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eWhite piedra\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eSDA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eSabouraud dextrose agar\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eAFST\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eAntifungal susceptibility test\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003ePCR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003ePolymerase Chain Reaction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eRFLP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eRestriction fragment\u0026nbsp;length polymorphism\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eCLSI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eClinical and Laboratories Standards Institute\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 28.2759%;\"\u003e\n \u003cp\u003eMIC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71.7241%;\"\u003e\n \u003cp\u003eMinimum inhibitory concentration\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge the active participation of all patients, health workers, and laboratory personnel at the burn hospitals who made this study feasible.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eT.S., A.M., and A.K. conceived and designed the study and final approval of the version to be published. T.S. and A.K. were involved in clinical data collection. A.M., M.S. S.M. and A.M. provided the microbiological report and wrote the draft. All authors have read, critically revised, and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSequence data were deposited into the GenBank database () under accession number PQ721052at the following URL: https://www.ncbi.nlm.nih.gov/nuccore/PQ721052\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Ethics Committee of Mazandaran University of Medical Sciences, Sari, Iran approved his report (IR.MAZUMS.REC.1403.421), and informed consent was obtained from the legal guardian to participate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that written informed consent has been obtained from the individual for the publication of any potentially identifiable images or data included in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors have no conflict of interest to declare to relation on this work.\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHavlickova B, Czaika VA, Friedrich M. 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Biofilm production and evaluation of antifungal susceptibility amongst clinical Candida spp. isolates, including strains of the Candida parapsilosis complex. Medical mycology. 2011;49(3):253-62.\u003c/li\u003e\n\u003cli\u003eOliveira MT, Specian AFL, Andrade CG, Fran\u0026ccedil;a EJ, Furlaneto-Maia L, Furlaneto MC. Interaction of Candida parapsilosis isolates with human hair and nail surfaces revealed by scanning electron microscopy analysis. Micron. 2010;41(6):604-8.\u003c/li\u003e\n\u003cli\u003eLarone D. Medically important fungi: a guide to identification. 2011.\u003c/li\u003e\n\u003cli\u003eKhullar G, Vignesh P, Lau YL, Rudramurthy SM, Rawat A, De D, et al. Chronic mucocutaneous candidiasis. The Journal of Allergy and Clinical Immunology: In Practice. 2017;5(4):1119-21.\u003cstrong\u003e\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Candida orthopsilosis, White piedra, Candida parapsilosis complex, Trichosporon beigelii","lastPublishedDoi":"10.21203/rs.3.rs-5819410/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5819410/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eWhite piedra (WP) is a fungal infection that affects hair shafts, resulting in the formation of soft nodules that can be white, gray, or brown. While it was initially believed to be caused by \u003cem\u003eTrichosporon beigelii\u003c/em\u003e, genetic analysis has reclassified \u003cem\u003eTrichosporon inkin\u003c/em\u003e, \u003cem\u003eT. ovoides\u003c/em\u003e, and \u003cem\u003eT. cutaneum\u003c/em\u003e, as the primary causative agents of WP. In this report, we present a rare documented case of WP caused by \u003cem\u003eCandida orthopsilosis\u003c/em\u003e, as a member of \u003cem\u003eCandida parapsilosis\u003c/em\u003e complex, occurring without presence of \u003cem\u003eTrichosporon\u003c/em\u003e in a temperate region in northern Iran.\u003c/p\u003e\u003ch2\u003eCase presentation\u003c/h2\u003e \u003cp\u003e: A 3-year-old girl visited a dermatology clinic with complaints of hair knots in the occipital area, particularly around the ears, that were difficult to remove. These symptoms have persisted for two months. The patient has no history of gym classes or kindergarten attendance and was not taking any specific medications. No other areas of her body were affected, and none of her family members reported experiencing any symptoms. Fungal isolates were identified using PCR-RFLP and confirmed by sequencing. Antifungal susceptibility testing of the isolates was conducted based on CLSI M27-S3 guidelines.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eWe suggest that \u003cem\u003eC. orthopsilosis\u003c/em\u003e can cause WP independently of \u003cem\u003eTrichosporon\u003c/em\u003e species, particularly in temperate regions. Future studies should establish a clear relationship between the yeast responsible for WP and its geographic location. This case could increase awareness among dermatologists and laboratory physicians, emphasizing that the growth of \u003cem\u003eCandida\u003c/em\u003e species should not be dismissed as contaminant.\u003c/p\u003e","manuscriptTitle":"A Rare Case of White Piedra Caused by Candida orthopsilosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-28 08:06:09","doi":"10.21203/rs.3.rs-5819410/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accepted","date":"2025-09-19T10:41:58+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-13T17:04:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-13T12:13:46+00:00","index":"hide","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-05T10:24:33+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"123076531110942659664759640724556113109","date":"2025-04-28T20:22:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"219708178776513473611483107408877146832","date":"2025-04-28T07:06:08+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-22T11:32:26+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-21T03:29:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2025-04-16T17:32:02+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f9f33acb-7293-4b64-bdce-fd571ee7488b","owner":[],"postedDate":"April 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-20T16:06:09+00:00","versionOfRecord":{"articleIdentity":"rs-5819410","link":"https://doi.org/10.1186/s12879-025-11787-5","journal":{"identity":"bmc-infectious-diseases","isVorOnly":false,"title":"BMC Infectious Diseases"},"publishedOn":"2025-10-15 15:56:52","publishedOnDateReadable":"October 15th, 2025"},"versionCreatedAt":"2025-04-28 08:06:09","video":"","vorDoi":"10.1186/s12879-025-11787-5","vorDoiUrl":"https://doi.org/10.1186/s12879-025-11787-5","workflowStages":[]},"version":"v1","identity":"rs-5819410","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5819410","identity":"rs-5819410","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}