Tinea Capitis Caused by Trichosporon asahii in an Immunocompetent Child: A Case Report

Tinea Capitis Caused by Trichosporon asahii in an Immunocompetent Child: A Case Report | 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 Tinea Capitis Caused by Trichosporon asahii in an Immunocompetent Child: A Case Report panling wei, xiaoli yang, zaixing wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6692251/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background：Trichosporon asahii is an emerging opportunistic yeast that often causes fatal disseminated infections in immunocompromised individuals. Due to the rarity of such infections, there is currently no standardized treatment guideline. Tinea capitis is the most common superficial fungal infection in children. In China, the predominant causative organisms include Microsporum canis, Trichophyton violaceum, T. mentagrophytes, T. tonsurans, and T. rubrum. Here, we report a rare case of tinea capitis caused by T. asahii in an immunocompetent child, which posed significant diagnostic and therapeutic challenges. Case presentation：The patient was a 4-year-old boy with a history of atopic dermatitis. Fungal cultures of purulent secretions from scalp lesions in the occipital region repeatedly yielded Trichosporon asahii. After hospital admission, he developed fever and worsening of his atopic dermatitis. Following systemic antifungal therapy with itraconazole and anti-inflammatory treatment with prednisone and dupilumab, his condition significantly improved. Both the scalp lesions and lymphadenopathy subsided, and follow-up showed sustained clinical remission. Conclusion：The diagnosis of Trichosporon infection relies on a high index of clinical suspicion and confirmation through microbiological testing. T. asahii can cause superficial fungal infections even in children without underlying conditions, underscoring the need for clinicians to remain vigilant in cases that respond poorly to conventional antifungal therapy. When necessary, definitive pathogen identification should be performed, and systemic antifungal treatment should be initiated early to improve clinical outcomes. Trichosporon asahii tinea capitis fungal infection child itraconazole Figures Figure 1 Figure 2 Figure 3 Background Trichosporon asahii (T. asahii) is a rare, emerging, non-Candida yeast-like fungus belonging to the class Basidiomycota and the order Trichosporonales. It is widely distributed in water, soil, and vegetation, and is known to colonize the skin, respiratory tract, genitourinary tract, and gastrointestinal tract of humans[ 1 ].In recent years, the incidence of T. asahii infections has shown a steady increase, predominantly affecting immunocompromised individuals[ 2 ].Reports have indicated that T. asahii can cause potentially fatal disseminated infections involving the brain, heart, lungs, liver, kidneys, and skin[ 3 ].Although deep-seated invasive infections are more common, T. asahii can also cause superficial infections in healthy individuals, albeit very rarely. Here, we report a case of tinea capitis caused by T. asahii in a child without evident immunodeficiency and review the relevant literature to raise clinical awareness of this unusual presentation. Case presentation A 4-year-old boy was admitted to our department on January 17, 2025, with complaints of painful scalp lesions for two weeks and scattered pruritic rashes on the trunk and limbs for three days.Two weeks prior to admission, his parents noticed patchy, dark-red papules and plaques on the vertex of the scalp, which gradually enlarged, ulcerated, and oozed yellowish and bloody discharge. The lesions were markedly tender on palpation and were accompanied by enlargement of superficial lymph nodes in the postauricular and occipital regions.The patient had been treated with oral cefaclor and topical mupirocin ointment, sulfur ointment, and hydrocortisone butyrate cream, but there was no significant improvement. Meanwhile, scattered light red papules gradually appeared over the trunk and extremities.Outpatient laboratory tests revealed leukocytosis (white blood cell count: 14.22 × 10⁹/L) with a neutrophil predominance (75.1%). Direct fungal microscopy of the lesions revealed positive hyphae.With an initial clinical impression of kerion and skin infection, the patient was admitted for further evaluation and management.During the disease course, the patient did not experience obvious fever or chills. He remained in good general condition with normal appetite, sleep, urination, and defecation. His past medical history was notable for asthma, allergic rhinitis, and atopic dermatitis. On admission, the patient’s vital signs were as follows: temperature 37.5°C, pulse 122 beats per minute, respiratory rate 22 breaths per minute, and blood pressure 85/58 mmHg. His height was 110 cm and weight 20 kg.Physical examination revealed multiple inflammatory nodules on the vertex of the scalp with surface erosion and purulent discharge (Fig. 1 ). Scattered light red papules were observed on the trunk and extremities. Enlarged lymph nodes were palpable in the postauricular and occipital regions. No other systemic abnormalities were noted on physical examination. Laboratory tests showed elevated white blood cell count (14.22 × 10⁹/L) with an increased neutrophil ratio (75.1%). Direct microscopic examination of scalp scales revealed numerous septate hyphae without visible conidia; hair shafts showed no fungal elements (Fig. 2 ). Immunologic, hepatic, renal, and biochemical tests were within normal limits.Multiple fungal cultures of purulent scalp secretions consistently grew Trichosporon asahii. Initial diagnosis included Trichosporon asahii infection, kerion, and moderate-to-severe atopic dermatitis. Initial treatment consisted of oral terbinafine hydrochloride tablets, topical chlortetracycline eye ointment, miconazole nitrate cream, and intravenous ceftriaxone. However, the patient developed a rising fever after admission, and erythematous papules on the trunk and face worsened markedly.Further investigations were performed, including blood culture, influenza A virus antigen test, and SARS-CoV-2 nucleic acid test, all of which were negative. Repeat culture of scalp exudate again yielded T. asahii. A follow-up complete blood count showed white blood cells at 13.28 × 10⁹/L and neutrophils at 73.1%. Serum total IgE was elevated at 190.82 IU/mL.The treatment regimen was subsequently adjusted to include oral itraconazole 50 mg twice daily, subcutaneous dupilumab 300 mg to control atopic inflammation, and oral cetirizine as an antihistamine. Despite the modified therapy, the patient continued to experience intermittent fever. Immunoglobulin levels, complement levels, lymphocyte subsets, and autoantibody panels were all within normal limits. Referral to a tertiary care hospital was recommended for further management.The patient was transferred to the National Center for Dermatology, Chinese Academy of Medical Sciences, for continued care. Two days after discharge, his body temperature returned to normal. Itraconazole was continued orally at a dose of 100 mg once daily. Oral prednisone 10 mg/day was added to control inflammation. After shaving the scalp, topical bifonazole cream was applied to the lesions.At 2-month follow-up, the scalp lesions had resolved, leaving pale red patches with yellowish crusts, and sparse regrowth of hair was observed in previously alopecic areas (Fig. 3 ). Repeated fungal microscopic examinations during follow-up were consistently negative. Prednisone was gradually tapered and maintained at a low dose, while dupilumab was continued for long-term control of atopic dermatitis. The patient remained in good clinical condition. Discussion and conclusion Discussion and conclusion According to the current literature, no cases of tinea capitis caused by Trichosporon asahii in immunocompetent children have been reported. The present case involved a previously healthy child with no evidence of immunodeficiency who developed typical clinical features of tinea capitis—including inflammatory scalp nodules, erosion, exudation, and regional lymphadenopathy—following infection with T. asahii. The condition responded poorly to conventional topical antifungal therapy but showed marked improvement after systemic antifungal treatment. This case provides valuable clinical insight into the diagnosis and management of rare fungal infections in pediatric populations. Tinea capitis is the most common dermatophytosis in children, primarily presenting with scalp erythema, scales, and hair loss. Some affected children may also exhibit pustular lesions. The onset of tinea capitis is closely related to factors such as age, hygiene, animal contact, and living environment[ 4 ].Studies both domestically and internationally have shown regional differences in the main pathogens of tinea capitis. In China, the most common pathogenic fungi include Microsporum canis, Trichophyton violaceum, and Trichophyton tonsurans[ 5 ].Traditional views suggest that non-dermatophyte fungi, such as yeasts or other opportunistic pathogens, are rare in superficial scalp infections. However, in recent years, with changes in the spectrum of fungal infections, the abuse of antibiotics, and an increase in immune-related diseases, some atypical fungi have gradually been confirmed to cause infections in the skin and even hair[ 6 ]. Asahii is a yeast-like fungus belonging to the Basidiomycota phylum and the Microsporal genus. It is widely present in nature, including in water, soil, air, and the normal microbiota of human skin, gastrointestinal tract, and other areas[ 7 ].In immunocompromised states, T. asahii often acts as an opportunistic pathogen, causing severe and even fatal disseminated infections, affecting multiple organs such as the lungs, liver, kidneys, and central nervous system, with a high mortality rate[ 8 ]. In contrast, reports of infections in immunocompetent individuals are rare, and these infections are often localized or superficial, typically found on mucous membranes [ 9 ], or in medical-related areas like urinary catheters[ 10 ], central venous catheters[ 11 ], etc. These infections are frequently misdiagnosed or missed. The treatment of dermatophyte infections remains challenging, primarily relying on antifungal therapy. For superficial infections, topical antifungal agents are typically used. However, patients with hair infections may experience relapse after local treatment. Some researchers suggest that in such cases, a combination of hair shaving and systemic antifungal treatment should be considered[ 12 ]. Increasing data suggests that amphotericin B has limited effectiveness in treating species of the Aspergillus genus, including T. asahii strains. Triazole antifungal drugs exhibit better in vitro and in vivo antifungal activity compared to amphotericin B[ 13 ]. In vitro studies have shown that voriconazole exhibits the best antifungal activity against various Aspergillus species compared to amphotericin B and fluconazole[ 14 ]. This result suggests that voriconazole may have significant potential in the treatment of related infections, providing further support for its clinical application. In this case, the child initially received ineffective topical treatment. After switching to systemic itraconazole combined with oral prednisone and dupilumab to control the allergic inflammatory response, the condition improved rapidly. This highlights the importance of considering non-dermatophyte fungal infections in difficult cases of tinea capitis and adjusting the treatment regimen promptly based on microbiological findings. Additionally, the child had a history of atopic dermatitis, allergic rhinitis, and other allergic conditions, suggesting that their skin barrier function may have been mildly impaired, potentially creating an opportunity for T. asahii to cause infection. This observation is consistent with some research reports, which indicate that even in individuals with normal immune function, dermatophyte infections, such as Aspergillus, can occur when the skin's integrity is compromised or the local environment is altered [ 15 ]. In summary, this case suggests that clinicians should be alert to the possibility of atypical pathogenic fungi in cases of persistent tinea capitis that do not respond to conventional treatment. Early fungal microscopy and culture to identify the pathogen, along with the rational selection of antifungal agents and adjunctive anti-inflammatory therapy, can help improve treatment success rates and reduce the risk of complications, misdiagnosis, and mistreatment. According to the current literature, no cases of tinea capitis caused by Trichosporon asahii in immunocompetent children have been reported. The present case involved a previously healthy child with no evidence of immunodeficiency who developed typical clinical features of tinea capitis—including inflammatory scalp nodules, erosion, exudation, and regional lymphadenopathy—following infection with T. asahii. The condition responded poorly to conventional topical antifungal therapy but showed marked improvement after systemic antifungal treatment. This case provides valuable clinical insight into the diagnosis and management of rare fungal infections in pediatric populations. Tinea capitis is the most common dermatophytosis in children, primarily presenting with scalp erythema, scales, and hair loss. Some affected children may also exhibit pustular lesions. The onset of tinea capitis is closely related to factors such as age, hygiene, animal contact, and living environment[ 4 ].Studies both domestically and internationally have shown regional differences in the main pathogens of tinea capitis. In China, the most common pathogenic fungi include Microsporum canis, Trichophyton violaceum, and Trichophyton tonsurans[ 5 ].Traditional views suggest that non-dermatophyte fungi, such as yeasts or other opportunistic pathogens, are rare in superficial scalp infections. However, in recent years, with changes in the spectrum of fungal infections, the abuse of antibiotics, and an increase in immune-related diseases, some atypical fungi have gradually been confirmed to cause infections in the skin and even hair[ 6 ]. Asahii is a yeast-like fungus belonging to the Basidiomycota phylum and the Microsporal genus. It is widely present in nature, including in water, soil, air, and the normal microbiota of human skin, gastrointestinal tract, and other areas[ 7 ].In immunocompromised states, T. asahii often acts as an opportunistic pathogen, causing severe and even fatal disseminated infections, affecting multiple organs such as the lungs, liver, kidneys, and central nervous system, with a high mortality rate[ 8 ]. In contrast, reports of infections in immunocompetent individuals are rare, and these infections are often localized or superficial, typically found on mucous membranes [ 9 ], or in medical-related areas like urinary catheters[ 10 ], central venous catheters[ 11 ], etc. These infections are frequently misdiagnosed or missed. The treatment of dermatophyte infections remains challenging, primarily relying on antifungal therapy. For superficial infections, topical antifungal agents are typically used. However, patients with hair infections may experience relapse after local treatment. Some researchers suggest that in such cases, a combination of hair shaving and systemic antifungal treatment should be considered[ 12 ]. Increasing data suggests that amphotericin B has limited effectiveness in treating species of the Aspergillus genus, including T. asahii strains. Triazole antifungal drugs exhibit better in vitro and in vivo antifungal activity compared to amphotericin B[ 13 ]. In vitro studies have shown that voriconazole exhibits the best antifungal activity against various Aspergillus species compared to amphotericin B and fluconazole[ 14 ]. This result suggests that voriconazole may have significant potential in the treatment of related infections, providing further support for its clinical application. In this case, the child initially received ineffective topical treatment. After switching to systemic itraconazole combined with oral prednisone and dupilumab to control the allergic inflammatory response, the condition improved rapidly. This highlights the importance of considering non-dermatophyte fungal infections in difficult cases of tinea capitis and adjusting the treatment regimen promptly based on microbiological findings. Additionally, the child had a history of atopic dermatitis, allergic rhinitis, and other allergic conditions, suggesting that their skin barrier function may have been mildly impaired, potentially creating an opportunity for T. asahii to cause infection. This observation is consistent with some research reports, which indicate that even in individuals with normal immune function, dermatophyte infections, such as Aspergillus, can occur when the skin's integrity is compromised or the local environment is altered [ 15 ]. In summary, this case suggests that clinicians should be alert to the possibility of atypical pathogenic fungi in cases of persistent tinea capitis that do not respond to conventional treatment. Early fungal microscopy and culture to identify the pathogen, along with the rational selection of antifungal agents and adjunctive anti-inflammatory therapy, can help improve treatment success rates and reduce the risk of complications, misdiagnosis, and mistreatment. Abbreviations T. asahii Trichosporon asahii Declarations Acknowledgements Not applicable. Authors ’ contributions WPL is the principle investigator of this manuscript. WPL and YXL conducted the data collection and performed literature review and drafted and edited the manuscript. WPL,YXL and WZX participated in the design, helped to draft and revise the manuscript. All authors read and approved the final manuscript. Funding This research did not receive any specific Grant from funding agencies in the public, commercial, or not-for-profit sector. Availability of data and materials All data are contained within the article. Ethics approval and consent to participate Not applicable. Consent for publication Written informed consent was obtained from the parents of the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal. Competing interests The authors declare that they have no competing interests. References Colombo A L, Padovan A C B, Chaves G M. Current Knowledge of Trichosporon spp. and Trichosporonosis[J]. Clinical Microbiology Reviews, 2011, 24(4): 682-700. De Almeida Júnior J N, Hennequin C. Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen[J]. Frontiers in Microbiology, 2016, 7. Li H, Guo M, Wang C, et al. Epidemiological study of Trichosporon asahii infections over the past 23 years[J]. Epidemiology and Infection, 2020, 148: e169. Gupta A K, Polla Ravi S, Wang T, et al. An update on tinea capitis in children[J]. Pediatric Dermatology, 2024, 41(6): 1030-1039. Xq C, J Y. Global demographic characteristics and pathogen spectrum of tinea capitis[J]. Mycopathologia, 2023, 188(5). Chanyachailert P, Leeyaphan C, Bunyaratavej S. Cutaneous fungal infections caused by dermatophytes and non-dermatophytes: an updated comprehensive review of epidemiology, clinical presentations, and diagnostic testing[J]. Journal of Fungi, 2023, 9(6): 669. Ruan S, Chien J, Hsueh P. Invasive Trichosporonosis Caused by Trichosporon asahii and Other Unusual Trichosporon Species at a Medical Center in Taiwan[J]. Clinical Infectious Diseases, 2009, 49(1): e11-e17. Miceli M H, Díaz J A, Lee S A. Emerging opportunistic yeast infections[J]. Lancet Infectious Diseases, 2011, 11(2): 142-151. Pulvirenti N, Dall’Oglio F, Greco A M, et al. Superficial cutaneous trichosporon asahii infection in an immunocompetent host[J]. International Journal of Dermatology, 2006, 45(12): 1428-1431. Urs T A, Kadiyala V, Deepak S, et al. Catheter associated urinary tract infections due to trichosporon asahii[J]. Journal of Laboratory Physicians, 2018, 10(4): 464-470. Bongomin F, Otu A, Calisti G, et al. Trichosporon japonicum fungemia and ventricular assist device infection in an immunocompetent patient[J]. Open Forum Infectious Diseases, 2019, 6(9): ofz343. Kiken D A, Sekaran A, Antaya R J, et al. White piedra in children[J]. Journal of the American Academy of Dermatology, 2006, 55(6): 956-961. Suzuki K, Nakase K, Kyo T, et al. Fatal Trichosporon fungemia in patients with hematologic malignancies[J]. European Journal of Haematology, 2010, 84(5): 441-447. Arendrup M C, Boekhout T, Akova M, et al. ESCMID† and ECMM‡ joint clinical guidelines for the diagnosis and management of rare invasive yeast infections[J]. Clinical Microbiology and Infection, 2014, 20: 76-98. Mulè A, Rossini F, Sollima A, et al. Trichosporon asahii infective endocarditis of prosthetic valve: a case report and literature review[J]. Antibiotics, 2023, 12(7): 1181. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-6692251","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":470246730,"identity":"f34157c5-5f76-4755-9acb-fbe2f592cf2b","order_by":0,"name":"panling wei","email":"","orcid":"","institution":"the First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"panling","middleName":"","lastName":"wei","suffix":""},{"id":470246731,"identity":"6eb4ca8b-e517-40bf-936f-2c71c941cbbd","order_by":1,"name":"xiaoli yang","email":"","orcid":"","institution":"the First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"xiaoli","middleName":"","lastName":"yang","suffix":""},{"id":470246732,"identity":"1cc5c70b-3482-4772-9897-51afad8ff247","order_by":2,"name":"zaixing wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAuklEQVRIiWNgGAWjYHACxocf/0nIsbG3HyBaC7OxBJuNMR/PmQSitbBJ8LClJc6TcDAgTr3B+TMGEhI8h9PbJBgSGH5UbCNCy4FjCQYFEodz26QbDzD2nLlNWIvZweYDCRIGQC0yBxKYGduI0XKYseEAT8LhdDaJBAMitRxjPtjAcyAtgXgt9mfYkpklG2wM24CBfJAov0j2nzH/+bFBQl6+vf3ggx8VRGhBAQdIVD8KRsEoGAWjABcAAPikO3ChcQXfAAAAAElFTkSuQmCC","orcid":"","institution":"the First Affiliated Hospital of Anhui Medical University","correspondingAuthor":true,"prefix":"","firstName":"zaixing","middleName":"","lastName":"wang","suffix":""}],"badges":[],"createdAt":"2025-05-18 14:23:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6692251/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6692251/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":84699700,"identity":"2faff71c-907a-4c9d-acad-e03e2b901e5d","added_by":"auto","created_at":"2025-06-16 11:12:55","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":245393,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMultiple inflammatory nodules on the top of the head, with erosion on the surface and purulent discharge.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6692251/v1/aee4f14dfb6d5ed124f097cc.png"},{"id":84700126,"identity":"e2b1b7bd-4c5a-4230-843c-c193cd69a12f","added_by":"auto","created_at":"2025-06-16 11:20:55","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":157921,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFungal direct microscopy (KOH treatment, ×400). Numerous transparent, branching hyphae are visible, arranged in an interwoven pattern, with a regular morphology and no spore structures observed\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6692251/v1/8b5bec2706c355cead78d100.png"},{"id":84699704,"identity":"010e35e1-248e-45e9-a69d-dee851095f17","added_by":"auto","created_at":"2025-06-16 11:12:55","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":125614,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTwo months after systemic treatment, dark red patches on the top of the head, with yellow crusted scales on the surface. Sparse new hair growth is visible in areas of diffuse hair loss.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6692251/v1/6ed81791ece2efdad8f50029.png"},{"id":85085991,"identity":"46b98500-7771-4022-b13f-4d2cb55c085c","added_by":"auto","created_at":"2025-06-20 19:31:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1242523,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6692251/v1/f855af97-daee-42e0-b004-00fc80234ca0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Tinea Capitis Caused by Trichosporon asahii in an Immunocompetent Child: A Case Report","fulltext":[{"header":"Background","content":"\u003cp\u003eTrichosporon asahii (T. asahii) is a rare, emerging, non-Candida yeast-like fungus belonging to the class Basidiomycota and the order Trichosporonales. It is widely distributed in water, soil, and vegetation, and is known to colonize the skin, respiratory tract, genitourinary tract, and gastrointestinal tract of humans[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].In recent years, the incidence of T. asahii infections has shown a steady increase, predominantly affecting immunocompromised individuals[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].Reports have indicated that T. asahii can cause potentially fatal disseminated infections involving the brain, heart, lungs, liver, kidneys, and skin[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].Although deep-seated invasive infections are more common, T. asahii can also cause superficial infections in healthy individuals, albeit very rarely.\u003c/p\u003e \u003cp\u003eHere, we report a case of tinea capitis caused by T. asahii in a child without evident immunodeficiency and review the relevant literature to raise clinical awareness of this unusual presentation.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 4-year-old boy was admitted to our department on January 17, 2025, with complaints of painful scalp lesions for two weeks and scattered pruritic rashes on the trunk and limbs for three days.Two weeks prior to admission, his parents noticed patchy, dark-red papules and plaques on the vertex of the scalp, which gradually enlarged, ulcerated, and oozed yellowish and bloody discharge. The lesions were markedly tender on palpation and were accompanied by enlargement of superficial lymph nodes in the postauricular and occipital regions.The patient had been treated with oral cefaclor and topical mupirocin ointment, sulfur ointment, and hydrocortisone butyrate cream, but there was no significant improvement. Meanwhile, scattered light red papules gradually appeared over the trunk and extremities.Outpatient laboratory tests revealed leukocytosis (white blood cell count: 14.22 × 10⁹/L) with a neutrophil predominance (75.1%). Direct fungal microscopy of the lesions revealed positive hyphae.With an initial clinical impression of kerion and skin infection, the patient was admitted for further evaluation and management.During the disease course, the patient did not experience obvious fever or chills. He remained in good general condition with normal appetite, sleep, urination, and defecation. His past medical history was notable for asthma, allergic rhinitis, and atopic dermatitis.\u003c/p\u003e \u003cp\u003eOn admission, the patient’s vital signs were as follows: temperature 37.5°C, pulse 122 beats per minute, respiratory rate 22 breaths per minute, and blood pressure 85/58 mmHg. His height was 110 cm and weight 20 kg.Physical examination revealed multiple inflammatory nodules on the vertex of the scalp with surface erosion and purulent discharge (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Scattered light red papules were observed on the trunk and extremities. Enlarged lymph nodes were palpable in the postauricular and occipital regions. No other systemic abnormalities were noted on physical examination.\u003c/p\u003e \u003cp\u003eLaboratory tests showed elevated white blood cell count (14.22 × 10⁹/L) with an increased neutrophil ratio (75.1%). Direct microscopic examination of scalp scales revealed numerous septate hyphae without visible conidia; hair shafts showed no fungal elements (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Immunologic, hepatic, renal, and biochemical tests were within normal limits.Multiple fungal cultures of purulent scalp secretions consistently grew Trichosporon asahii.\u003c/p\u003e \u003cp\u003eInitial diagnosis included Trichosporon asahii infection, kerion, and moderate-to-severe atopic dermatitis.\u003c/p\u003e \u003cp\u003eInitial treatment consisted of oral terbinafine hydrochloride tablets, topical chlortetracycline eye ointment, miconazole nitrate cream, and intravenous ceftriaxone. However, the patient developed a rising fever after admission, and erythematous papules on the trunk and face worsened markedly.Further investigations were performed, including blood culture, influenza A virus antigen test, and SARS-CoV-2 nucleic acid test, all of which were negative. Repeat culture of scalp exudate again yielded T. asahii. A follow-up complete blood count showed white blood cells at 13.28 × 10⁹/L and neutrophils at 73.1%. Serum total IgE was elevated at 190.82 IU/mL.The treatment regimen was subsequently adjusted to include oral itraconazole 50 mg twice daily, subcutaneous dupilumab 300 mg to control atopic inflammation, and oral cetirizine as an antihistamine. Despite the modified therapy, the patient continued to experience intermittent fever. Immunoglobulin levels, complement levels, lymphocyte subsets, and autoantibody panels were all within normal limits. Referral to a tertiary care hospital was recommended for further management.The patient was transferred to the National Center for Dermatology, Chinese Academy of Medical Sciences, for continued care. Two days after discharge, his body temperature returned to normal. Itraconazole was continued orally at a dose of 100 mg once daily. Oral prednisone 10 mg/day was added to control inflammation. After shaving the scalp, topical bifonazole cream was applied to the lesions.At 2-month follow-up, the scalp lesions had resolved, leaving pale red patches with yellowish crusts, and sparse regrowth of hair was observed in previously alopecic areas (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Repeated fungal microscopic examinations during follow-up were consistently negative. Prednisone was gradually tapered and maintained at a low dose, while dupilumab was continued for long-term control of atopic dermatitis. The patient remained in good clinical condition.\u003c/p\u003e "},{"header":"Discussion and conclusion","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eDiscussion and conclusion\u003c/h2\u003e \u003cp\u003eAccording to the current literature, no cases of tinea capitis caused by Trichosporon asahii in immunocompetent children have been reported. The present case involved a previously healthy child with no evidence of immunodeficiency who developed typical clinical features of tinea capitis—including inflammatory scalp nodules, erosion, exudation, and regional lymphadenopathy—following infection with T. asahii. The condition responded poorly to conventional topical antifungal therapy but showed marked improvement after systemic antifungal treatment. This case provides valuable clinical insight into the diagnosis and management of rare fungal infections in pediatric populations.\u003c/p\u003e \u003cp\u003eTinea capitis is the most common dermatophytosis in children, primarily presenting with scalp erythema, scales, and hair loss. Some affected children may also exhibit pustular lesions. The onset of tinea capitis is closely related to factors such as age, hygiene, animal contact, and living environment[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].Studies both domestically and internationally have shown regional differences in the main pathogens of tinea capitis. In China, the most common pathogenic fungi include Microsporum canis, Trichophyton violaceum, and Trichophyton tonsurans[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].Traditional views suggest that non-dermatophyte fungi, such as yeasts or other opportunistic pathogens, are rare in superficial scalp infections. However, in recent years, with changes in the spectrum of fungal infections, the abuse of antibiotics, and an increase in immune-related diseases, some atypical fungi have gradually been confirmed to cause infections in the skin and even hair[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAsahii is a yeast-like fungus belonging to the Basidiomycota phylum and the Microsporal genus. It is widely present in nature, including in water, soil, air, and the normal microbiota of human skin, gastrointestinal tract, and other areas[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].In immunocompromised states, T. asahii often acts as an opportunistic pathogen, causing severe and even fatal disseminated infections, affecting multiple organs such as the lungs, liver, kidneys, and central nervous system, with a high mortality rate[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In contrast, reports of infections in immunocompetent individuals are rare, and these infections are often localized or superficial, typically found on mucous membranes [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], or in medical-related areas like urinary catheters[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], central venous catheters[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], etc. These infections are frequently misdiagnosed or missed.\u003c/p\u003e \u003cp\u003eThe treatment of dermatophyte infections remains challenging, primarily relying on antifungal therapy. For superficial infections, topical antifungal agents are typically used. However, patients with hair infections may experience relapse after local treatment. Some researchers suggest that in such cases, a combination of hair shaving and systemic antifungal treatment should be considered[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Increasing data suggests that amphotericin B has limited effectiveness in treating species of the Aspergillus genus, including T. asahii strains. Triazole antifungal drugs exhibit better in vitro and in vivo antifungal activity compared to amphotericin B[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In vitro studies have shown that voriconazole exhibits the best antifungal activity against various Aspergillus species compared to amphotericin B and fluconazole[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This result suggests that voriconazole may have significant potential in the treatment of related infections, providing further support for its clinical application. In this case, the child initially received ineffective topical treatment. After switching to systemic itraconazole combined with oral prednisone and dupilumab to control the allergic inflammatory response, the condition improved rapidly. This highlights the importance of considering non-dermatophyte fungal infections in difficult cases of tinea capitis and adjusting the treatment regimen promptly based on microbiological findings.\u003c/p\u003e \u003cp\u003eAdditionally, the child had a history of atopic dermatitis, allergic rhinitis, and other allergic conditions, suggesting that their skin barrier function may have been mildly impaired, potentially creating an opportunity for T. asahii to cause infection. This observation is consistent with some research reports, which indicate that even in individuals with normal immune function, dermatophyte infections, such as Aspergillus, can occur when the skin's integrity is compromised or the local environment is altered [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn summary, this case suggests that clinicians should be alert to the possibility of atypical pathogenic fungi in cases of persistent tinea capitis that do not respond to conventional treatment. Early fungal microscopy and culture to identify the pathogen, along with the rational selection of antifungal agents and adjunctive anti-inflammatory therapy, can help improve treatment success rates and reduce the risk of complications, misdiagnosis, and mistreatment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\u003cp\u003eAccording to the current literature, no cases of tinea capitis caused by Trichosporon asahii in immunocompetent children have been reported. The present case involved a previously healthy child with no evidence of immunodeficiency who developed typical clinical features of tinea capitis—including inflammatory scalp nodules, erosion, exudation, and regional lymphadenopathy—following infection with T. asahii. The condition responded poorly to conventional topical antifungal therapy but showed marked improvement after systemic antifungal treatment. This case provides valuable clinical insight into the diagnosis and management of rare fungal infections in pediatric populations.\u003c/p\u003e\u003cp\u003eTinea capitis is the most common dermatophytosis in children, primarily presenting with scalp erythema, scales, and hair loss. Some affected children may also exhibit pustular lesions. The onset of tinea capitis is closely related to factors such as age, hygiene, animal contact, and living environment[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].Studies both domestically and internationally have shown regional differences in the main pathogens of tinea capitis. In China, the most common pathogenic fungi include Microsporum canis, Trichophyton violaceum, and Trichophyton tonsurans[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].Traditional views suggest that non-dermatophyte fungi, such as yeasts or other opportunistic pathogens, are rare in superficial scalp infections. However, in recent years, with changes in the spectrum of fungal infections, the abuse of antibiotics, and an increase in immune-related diseases, some atypical fungi have gradually been confirmed to cause infections in the skin and even hair[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAsahii is a yeast-like fungus belonging to the Basidiomycota phylum and the Microsporal genus. It is widely present in nature, including in water, soil, air, and the normal microbiota of human skin, gastrointestinal tract, and other areas[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].In immunocompromised states, T. asahii often acts as an opportunistic pathogen, causing severe and even fatal disseminated infections, affecting multiple organs such as the lungs, liver, kidneys, and central nervous system, with a high mortality rate[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In contrast, reports of infections in immunocompetent individuals are rare, and these infections are often localized or superficial, typically found on mucous membranes [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], or in medical-related areas like urinary catheters[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], central venous catheters[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], etc. These infections are frequently misdiagnosed or missed.\u003c/p\u003e\u003cp\u003eThe treatment of dermatophyte infections remains challenging, primarily relying on antifungal therapy. For superficial infections, topical antifungal agents are typically used. However, patients with hair infections may experience relapse after local treatment. Some researchers suggest that in such cases, a combination of hair shaving and systemic antifungal treatment should be considered[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Increasing data suggests that amphotericin B has limited effectiveness in treating species of the Aspergillus genus, including T. asahii strains. Triazole antifungal drugs exhibit better in vitro and in vivo antifungal activity compared to amphotericin B[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In vitro studies have shown that voriconazole exhibits the best antifungal activity against various Aspergillus species compared to amphotericin B and fluconazole[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This result suggests that voriconazole may have significant potential in the treatment of related infections, providing further support for its clinical application. In this case, the child initially received ineffective topical treatment. After switching to systemic itraconazole combined with oral prednisone and dupilumab to control the allergic inflammatory response, the condition improved rapidly. This highlights the importance of considering non-dermatophyte fungal infections in difficult cases of tinea capitis and adjusting the treatment regimen promptly based on microbiological findings.\u003c/p\u003e\u003cp\u003eAdditionally, the child had a history of atopic dermatitis, allergic rhinitis, and other allergic conditions, suggesting that their skin barrier function may have been mildly impaired, potentially creating an opportunity for T. asahii to cause infection. This observation is consistent with some research reports, which indicate that even in individuals with normal immune function, dermatophyte infections, such as Aspergillus, can occur when the skin's integrity is compromised or the local environment is altered [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn summary, this case suggests that clinicians should be alert to the possibility of atypical pathogenic fungi in cases of persistent tinea capitis that do not respond to conventional treatment. Early fungal microscopy and culture to identify the pathogen, along with the rational selection of antifungal agents and adjunctive anti-inflammatory therapy, can help improve treatment success rates and reduce the risk of complications, misdiagnosis, and mistreatment.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eT. asahii\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTrichosporon asahii\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNot applicable. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u003c/strong\u003e\u003cstrong\u003e\u0026rsquo;\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWPL is the principle investigator of this manuscript. WPL and YXL conducted the data collection and performed literature review and drafted and edited the manuscript. WPL,YXL and WZX participated in the design, helped to draft and revise the manuscript. All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific Grant from funding agencies in the public, commercial, or not-for-profit sector. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data are contained within the article. \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the parents of the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eColombo A L, Padovan A C B, Chaves G M. Current Knowledge of Trichosporon spp. and Trichosporonosis[J]. Clinical Microbiology Reviews, 2011, 24(4): 682-700.\u003c/li\u003e\n\u003cli\u003eDe Almeida J\u0026uacute;nior J N, Hennequin C. Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen[J]. Frontiers in Microbiology, 2016, 7.\u003c/li\u003e\n\u003cli\u003eLi H, Guo M, Wang C, et al. Epidemiological study of Trichosporon asahii infections over the past 23 years[J]. Epidemiology and Infection, 2020, 148: e169.\u003c/li\u003e\n\u003cli\u003eGupta A K, Polla Ravi S, Wang T, et al. An update on tinea capitis in children[J]. Pediatric Dermatology, 2024, 41(6): 1030-1039.\u003c/li\u003e\n\u003cli\u003eXq C, J Y. Global demographic characteristics and pathogen spectrum of tinea capitis[J]. Mycopathologia, 2023, 188(5).\u003c/li\u003e\n\u003cli\u003eChanyachailert P, Leeyaphan C, Bunyaratavej S. Cutaneous fungal infections caused by dermatophytes and non-dermatophytes: an updated comprehensive review of epidemiology, clinical presentations, and diagnostic testing[J]. Journal of Fungi, 2023, 9(6): 669.\u003c/li\u003e\n\u003cli\u003eRuan S, Chien J, Hsueh P. Invasive Trichosporonosis Caused by Trichosporon asahii and Other Unusual Trichosporon Species at a Medical Center in Taiwan[J]. Clinical Infectious Diseases, 2009, 49(1): e11-e17.\u003c/li\u003e\n\u003cli\u003eMiceli M H, D\u0026iacute;az J A, Lee S A. Emerging opportunistic yeast infections[J]. Lancet Infectious Diseases, 2011, 11(2): 142-151.\u003c/li\u003e\n\u003cli\u003ePulvirenti N, Dall\u0026rsquo;Oglio F, Greco A M, et al. Superficial cutaneous trichosporon asahii infection in an immunocompetent host[J]. International Journal of Dermatology, 2006, 45(12): 1428-1431.\u003c/li\u003e\n\u003cli\u003eUrs T A, Kadiyala V, Deepak S, et al. Catheter associated urinary tract infections due to trichosporon asahii[J]. Journal of Laboratory Physicians, 2018, 10(4): 464-470.\u003c/li\u003e\n\u003cli\u003eBongomin F, Otu A, Calisti G, et al. Trichosporon japonicum fungemia and ventricular assist device infection in an immunocompetent patient[J]. Open Forum Infectious Diseases, 2019, 6(9): ofz343.\u003c/li\u003e\n\u003cli\u003eKiken D A, Sekaran A, Antaya R J, et al. White piedra in children[J]. Journal of the American Academy of Dermatology, 2006, 55(6): 956-961.\u003c/li\u003e\n\u003cli\u003eSuzuki K, Nakase K, Kyo T, et al. Fatal Trichosporon fungemia in patients with hematologic malignancies[J]. European Journal of Haematology, 2010, 84(5): 441-447.\u003c/li\u003e\n\u003cli\u003eArendrup M C, Boekhout T, Akova M, et al. ESCMID\u0026dagger; and ECMM\u0026Dagger; joint clinical guidelines for the diagnosis and management of rare invasive yeast infections[J]. Clinical Microbiology and Infection, 2014, 20: 76-98.\u003c/li\u003e\n\u003cli\u003eMul\u0026egrave; A, Rossini F, Sollima A, et al. Trichosporon asahii infective endocarditis of prosthetic valve: a case report and literature review[J]. Antibiotics, 2023, 12(7): 1181. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Trichosporon asahii, tinea capitis, fungal infection, child, itraconazole","lastPublishedDoi":"10.21203/rs.3.rs-6692251/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6692251/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground：Trichosporon asahii is an emerging opportunistic yeast that often causes fatal disseminated infections in immunocompromised individuals. Due to the rarity of such infections, there is currently no standardized treatment guideline.\u003c/p\u003e\n\u003cp\u003eTinea capitis is the most common superficial fungal infection in children. In China, the predominant causative organisms include Microsporum canis, Trichophyton violaceum, T. mentagrophytes, T. tonsurans, and T. rubrum.\u003c/p\u003e\n\u003cp\u003eHere, we report a rare case of tinea capitis caused by T. asahii in an immunocompetent child, which posed significant diagnostic and therapeutic challenges.\u003c/p\u003e\n\u003cp\u003eCase presentation：The patient was a 4-year-old boy with a history of atopic dermatitis. Fungal cultures of purulent secretions from scalp lesions in the occipital region repeatedly yielded Trichosporon asahii. After hospital admission, he developed fever and worsening of his atopic dermatitis. Following systemic antifungal therapy with itraconazole and anti-inflammatory treatment with prednisone and dupilumab, his condition significantly improved. Both the scalp lesions and lymphadenopathy subsided, and follow-up showed sustained clinical remission.\u003c/p\u003e\n\u003cp\u003eConclusion：The diagnosis of Trichosporon infection relies on a high index of clinical suspicion and confirmation through microbiological testing. T. asahii can cause superficial fungal infections even in children without underlying conditions, underscoring the need for clinicians to remain vigilant in cases that respond poorly to conventional antifungal therapy. When necessary, definitive pathogen identification should be performed, and systemic antifungal treatment should be initiated early to improve clinical outcomes.\u003c/p\u003e","manuscriptTitle":"Tinea Capitis Caused by Trichosporon asahii in an Immunocompetent Child: A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-16 11:12:50","doi":"10.21203/rs.3.rs-6692251/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5a0dfffe-db57-4154-8c44-19c2c84088c7","owner":[],"postedDate":"June 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-06-20T19:23:20+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-16 11:12:50","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6692251","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6692251","identity":"rs-6692251","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}