Episcleritis Preceding Acute Syphilitic Posterior Placoid Chorioretinopathy in an Immunocompetent Patient: A Case Report

Episcleritis Preceding Acute Syphilitic Posterior Placoid Chorioretinopathy in an Immunocompetent Patient: 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 Episcleritis Preceding Acute Syphilitic Posterior Placoid Chorioretinopathy in an Immunocompetent Patient: A Case Report Abbas Abdel Sater This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9254419/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 To report the case of an immunocompetent 64-year-old man with acute syphilitic posterior placoid chorioretinitis with concurrent ipsilateral episcleritis. Case presentation: The patient first came with sectoral redness in the right eye and was diagnosed with acute episcleritis. At that time, treatment was limited to artificial tears. About four months later, the patient returned because of persistent episcleritis in the right eye and the vision had noticeably worsened; visual acuity had declined from BCVA 20/32 to 20/80. In the view of this, topical prednisolone was initiated at a frequency of three times daily. Fundus examination of the posterior segment revealed a large yellowish placoid lesion involving the posterior pole. The clinical appearance was concerning for acute syphilitic posterior placoid chorioretinopathy (ASPPC). Multimodal imaging was subsequently performed. Fluorescein angiography interpretation was limited due to coexisting diabetic retinopathy and myopic fundus changes, which may have confounded the angiographic finding. Optical coherence tomography showed disruption of the outer retinal layers. Subsequent serologic testing confirmed syphilis, and the patient was evaluated for possible neurosyphilis. Treatment with systemic penicillin was initiated, after which both the episcleritis and visual acuity gradually improved. Conclusions Episcleritis that presents as an isolated red eye, in the absence of systemic symptoms or visual decrease, may represent an early manifestation of ocular syphilis in immunocompetent patient. Notably, the coexistence of episcleritis with placoid posterior chorioretinitis must raise prompt suspicion for syphilis. Early recognition of this association is crucial, given that delayed recognition may result in preventable, vision-threatening complications. Syphilis ocular syphilis chorioretinopathy episcleritis Treponema pallidum Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Syphilis, a multisystem disease, is caused by Treponema pallidum which can affect the eye at any stage leading to progressive, and sometimes irreversible, vision loss [ 1 ]. The World Health Organisation (WHO) estimated 8 million adults aged 15–49 years acquired syphilis worldwide in 2022, highlighting the ongoing global outbreak of this infection [ 2 ]. Ocular syphilis, known as “greater masquerade”, reports several clinical presentations that mimic different inflammatory and infectious cases, making it harder to immediately diagnose it but rather delayed diagnosis and inappropriate treatment [ 3 ]. Ocular syphilis is commonly described in immunocompromised patients, often those infected with human immunodeficiency virus (HIV) where the symptoms are often more frequent and severe [ 4 ]. This association has heightened clinical suspicion in high-risk populations presenting with posterior placoid chorioretinitis, necrotizing retinitis, or panuveitis. Earlier recognition of ocular syphilis is better to avoid any permanent visual damage and the intervention of harmful therapies as corticosteroid monotherapy. However, ocular syphilis might appear in immunocompetent patients in less severe or uncommon forms, making diagnosis more difficult. Although previous case report has described episcleritis as an initial manifestation of syphilis [ 5 ], to our knowledge, none have linked the episcleritis occurring together acute syphilitic posterior placoid chorioretinopathy (ASPPC) as an early manifestation of syphilis. In this case report, the case of acute syphilitic posterior placoid chorioretinopathy in an immunocompetent patient who initially presented with isolated episcleritis without visual symptoms is reported. This underscores the importance of not underestimating persistent episcleritis, particularly if associated with chorioretinitis. Case presentation A 64-year-old immunocompetent male was initially presented with acute episcleritis of the right eye (OD) and then treated with artificial tears. Four months later, he returned with persistent episcleritis, but this time with progressive visual decline; with best-corrected visual acuity (BCVA) decreasing from 20/32 to 20/80 OD. Waiting for the coming examination, topical prednisolone was started three times daily. The dilated fundus examination demonstrated a large, yellowish placoid lesion at the level of the superior vascular arcade extending to the macula (Fig. 1 ). Optical coherence tomography (OCT) revealed subfoveal thickening and nodularity of the retinal pigment epithelium, with disruption of the adjacent photoreceptor inner segment–outer segment junction (Fig. 2 ). Fluorescein angiography demonstrated late-staining hyperfluorescence (Fig. 3 ). The fundus autofluorescence (Fig. 4 ) confirmed a more clearly delineated lesion, with distinct borders of hyperautofluorescence, and allowed better structural characterization. Serologic testing subsequently confirmed the diagnosis of syphilis (serum TPHA 1:2560, FTA-ABS IgG 1:5120, RPR 1:128), and an evaluation for neurosyphilis was undertaken. Cerebrospinal fluid analysis revealed pleocytosis (23/µL, lymphocytic), reactive TPHA (1:256), FTA-ABS IgG (1:256), RPR (1:2), and an elevated ITpA index of 12.6. At that time, systemic penicillin therapy was initiated at a dose of 25 million IU per day intravenously for 14 days. Over the following weeks, the patient showed steady improvement in both episcleritis and visual acuity. All the materials and methods that are used to complete the study should be mentioned. Discussions and Conclusions Syphilis is a multisystem infectious disease caused by the spirochete Treponema pallidum and remains a diagnostic challenge due to its protean clinical manifestations. Ocular syphilis, often referred to as the “great masquerade,” can involve nearly any ocular structure and may be the sole presenting feature of systemic infection. Because of its variable presentation, diagnosis may be delayed, particularly in patients without systemic symptoms or identifiable risk factors. The patient developed acute syphilitic posterior placoid chorioretinopathy (ASPPC), a distinctive manifestation characterized by large yellowish placoid lesions at the posterior pole [ 6 ]. ASPPC commonly presents with outer retinal disruption on optical coherence tomography (OCT), as abnormalities of the retinal pigment epithelium and photoreceptor layers, which were consistent with this case. Inflammatory involvement of the choriocapillaris–retinal pigment epithelium–photoreceptor complex is usually revealed by fluorescein angiography that commonly demonstrates late staining or hyperfluorescence of the lesion [ 7 ]. However, in this case study, the interpretation was limited by coexisting diabetic retinopathy and myopic fundus changes, which may have contributed to nonspecific hyperfluorescent patterns. To explain, coexisting diabetic retinopathy and myopic fundus changes can produce background microvascular leakage, window defects, and chorioretinal atrophy, reducing the diagnostic specificity of fluorescein angiography findings. Prompt recognition and treatment with systemic penicillin generally result in favourable anatomical and visual outcomes, as observed in our patient [ 8 , 9 ]. ASPPC has been more frequently reported in immunocompromised individuals, particularly in association with human immunodeficiency virus (HIV) infection [ 10 ]. However, increasing reports in immunocompetent patients highlight that absence of immunosuppression does not preclude the diagnosis. In such individuals, clinical suspicion may be lower, contributing to delayed diagnosis. A very important feature in this studied case is the initial presentation with isolated episcleritis which is typically regarded as benign and self-limited, later associating with acute syphilitic posterior placoid chorioretinopathy. Episcleritis is most often idiopathic and rarely associated with severe intraocular pathology [ 11 ]. In this patient, ipsilateral episcleritis persisted for several months prior to the development of posterior segment changes and the onset of visual decline. The patient’s early inflammation was most probably consistent with an initial manifestation of ocular syphilis. Systemic infectious causes, including syphilis, should be considered when episcleritis does not resolve as expected or when it is followed by new visual complaints. Although episcleritis is often regarded as a benign and self-limited condition, this case demonstrates that what appears to be a simple episcleritis, particularly when accompanied with posterior segment inflammation, can reflect a more serious ocular complication. In this patient, the initial presentation of isolated episcleritis with no systemic symptoms, and preserved visual acuity contributed to a delay in diagnosis of ocular syphilis. The later development of acute syphilitic posterior placoid chorioretinopathy with progressive visual decrease demonstrates how inflammation that appears mild and limited to the anterior segment can sometimes precede posterior segment inflammation. For patients with persistent or unexplained episcleritis, early serologic testing and a careful examination of the posterior segment are advisable. In such cases, taking the time to revisit the patient’s history, especially looking for subtle systemic symptoms, can uncover valuable diagnostic clues. As ocular syphilis continues to re-emerge worldwide, ophthalmologists must remain alert in atypical or non-resolving cases of episcleritis, particularly when accompanied with posterior segment inflammation, to secure an accurate diagnosis and reduce the risk of permanent visual loss. Abbreviations ASPPC Acute Syphilitic Posterior Placoid Chorioretinopathy BCVA Best–Corrected Visual Acuity FAF Fundus autofluorescence FTA ABS–Fluorescent Treponemal Antibody Absorption HIV Human Immunodeficiency Virus IU International Units OD Oculus Dexter (Right Eye) OCT Optical Coherence Tomography RPR Rapid Plasma Reagin TPHA Treponema Pallidum Hemagglutination Assay WHO World Health Organization Declarations Ethics approval and consent to participate Not applicable. Consent for publication Written informed consent was obtained from the patient for publication of this case report and accompanying images. Availability of data and materials The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author. Competing interest The author declares no competing interests. Acknowledgements The author has no acknowledgements to declare. Funding No funding was received for this study. References Ye Z, Yang M, Zou Y, et al. Syphilis and the Eye: Clinical Features, Diagnostic Challenges, and Evolving Therapeutic Paradigms. Pathogens. 2025;14(9):852. 10.3390/pathogens14090852 . World Health Organization. Sexually transmitted infections (STIs). 2022. Accessed February 18, 2026. https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis ). Park SW, Kim KH, Kwon HJ, Byon IS, Khan YH, Nguyen QD. Ocular syphilis masquerading as refractory retinal diseases. BMC Infect Dis. 2024;24(1):165. 10.1186/s12879-023-08739-2 . Cope AB, Mobley VL, Oliver SE, et al. Ocular Syphilis and Human Immunodeficiency Virus Coinfection Among Syphilis Patients in North Carolina, 2014–2016. Sex Transm Dis. 2019;46(2):80–5. 10.1097/OLQ.0000000000000910 . Wilhelmus KR, Yokoyama CM. Syphilitic Episcleritis and Scleritis. Am J Ophthalmol. 1987;104(6):595–7. 10.1016/0002-9394(87)90170-X . Neri P, Pichi F. Acute syphilitic posterior placoid chorioretinitis: when the great mimicker cannot pretend any more; new insight of an old acquaintance. J Ophthalmic Inflamm Infect. 2022;12(1):9. 10.1186/s12348-022-00286-2 . Barikian A, Davis J, Gregori G, Rosenfeld P. Wide field swept source OCT angiography in acute syphilitic placoid chorioretinitis. Am J Ophthalmol Case Rep. 2020;18:100678. 10.1016/j.ajoc.2020.100678 . Browning DJ. Posterior segment manifestations of active ocular syphilis, their response to a neurosyphilis regimen of penicillin therapy, and the influence of human immunodeficiency virus status on response. Ophthalmology. 2000;107(11):2015–23. 10.1016/S0161-6420(00)00457-7 . Wilson K, Garbo Maxey A. Acute Syphilitic Posterior Placoid Chorioretinitis; a Case Report and Review. Optom Clin Pract. 2023;5(1):18–28. 10.37685/uiwlibraries.2575-7717.5.1.1003 . Mitchell JP, Huang LL, Rosberger DF. Ocular syphilis in patients with Human Immunodeficiency Virus infection. J Natl Med Assoc. 2015;107(2):130–2. 10.1016/S0027-9684(15)30037-7 . Akpek E. Severity of episcleritis and systemic disease association. Ophthalmology. 1999;106(4):729–31. 10.1016/S0161-6420(99)90157-4 . 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. 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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-9254419","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":616098786,"identity":"e2738129-8dc0-40be-86bf-9f3d99efdfe4","order_by":0,"name":"Abbas Abdel Sater","email":"data:image/png;base64,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","orcid":"","institution":"Smile Eyes Medical Care Center for Ophthalmology","correspondingAuthor":true,"prefix":"","firstName":"Abbas","middleName":"Abdel","lastName":"Sater","suffix":""}],"badges":[],"createdAt":"2026-03-28 17:23:42","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9254419/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9254419/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106309812,"identity":"48e605de-2a9b-4b0f-b149-9841e92a9c14","added_by":"auto","created_at":"2026-04-07 10:20:01","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":346748,"visible":true,"origin":"","legend":"\u003cp\u003eColour fundus photograph of the right eye demonstrating a large yellowish placoid lesion located at the level of the superior vascular arcade and extended to the macula.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9254419/v1/6ecb0b518f5704f6cf90d76b.jpeg"},{"id":106309813,"identity":"bbc2850a-c34e-4fd2-a372-25b2ae4ab481","added_by":"auto","created_at":"2026-04-07 10:20:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":895857,"visible":true,"origin":"","legend":"\u003cp\u003eRight eye optical coherence tomography showing subfoveal thickening and nodularity of the retinal pigment epithelium, with disruption of the adjacent photoreceptor inner segment–outer segment junction.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-9254419/v1/f108dd3e09c59cecc3ed4c6b.png"},{"id":106404240,"identity":"c165d8e1-ada7-4b6b-850f-f5e8ab8520fc","added_by":"auto","created_at":"2026-04-08 09:15:42","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":280922,"visible":true,"origin":"","legend":"\u003cp\u003eLate-phase fluorescein angiography of the right eye demonstrating nonspecific hyperfluorescent patterns.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-9254419/v1/a4da23d7d51aee2b0ba69122.png"},{"id":106309815,"identity":"d1b5741d-f284-4160-ba54-bf7bc537b9e0","added_by":"auto","created_at":"2026-04-07 10:20:02","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":295428,"visible":true,"origin":"","legend":"\u003cp\u003eFundus autofluorescence (FAF) photos showing the distinct borders of hyperfluorescence (black arrow).\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-9254419/v1/9583343e54ed2eb3fae27e3b.png"},{"id":108962336,"identity":"17307078-076d-46e6-b133-c5641db67df1","added_by":"auto","created_at":"2026-05-11 09:00:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1934431,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9254419/v1/9a23a679-a1c4-48ce-bd21-adf7b86705d0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Episcleritis Preceding Acute Syphilitic Posterior Placoid Chorioretinopathy in an Immunocompetent Patient: A Case Report","fulltext":[{"header":"Background","content":"\u003cp\u003eSyphilis, a multisystem disease, is caused by \u003cem\u003eTreponema pallidum\u003c/em\u003e which can affect the eye at any stage leading to progressive, and sometimes irreversible, vision loss [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e]. The World Health Organisation (WHO) estimated 8\u0026nbsp;million adults aged 15–49 years acquired syphilis worldwide in 2022, highlighting the ongoing global outbreak of this infection [\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e]. Ocular syphilis, known as “greater masquerade”, reports several clinical presentations that mimic different inflammatory and infectious cases, making it harder to immediately diagnose it but rather delayed diagnosis and inappropriate treatment [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOcular syphilis is commonly described in immunocompromised patients, often those infected with human immunodeficiency virus (HIV) where the symptoms are often more frequent and severe [\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e]. This association has heightened clinical suspicion in high-risk populations presenting with posterior placoid chorioretinitis, necrotizing retinitis, or panuveitis. Earlier recognition of ocular syphilis is better to avoid any permanent visual damage and the intervention of harmful therapies as corticosteroid monotherapy.\u003c/p\u003e \u003cp\u003eHowever, ocular syphilis might appear in immunocompetent patients in less severe or uncommon forms, making diagnosis more difficult. Although previous case report has described episcleritis as an initial manifestation of syphilis [\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e], to our knowledge, none have linked the episcleritis occurring together acute syphilitic posterior placoid chorioretinopathy (ASPPC) as an early manifestation of syphilis.\u003c/p\u003e \u003cp\u003eIn this case report, the case of acute syphilitic posterior placoid chorioretinopathy in an immunocompetent patient who initially presented with isolated episcleritis without visual symptoms is reported. This underscores the importance of not underestimating persistent episcleritis, particularly if associated with chorioretinitis.\u003c/p\u003e "},{"header":"Case presentation","content":"\u003cp\u003eA 64-year-old immunocompetent male was initially presented with acute episcleritis of the right eye (OD) and then treated with artificial tears. Four months later, he returned with persistent episcleritis, but this time with progressive visual decline; with best-corrected visual acuity (BCVA) decreasing from 20/32 to 20/80 OD. Waiting for the coming examination, topical prednisolone was started three times daily. The dilated fundus examination demonstrated a large, yellowish placoid lesion at the level of the superior vascular arcade extending to the macula (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Optical coherence tomography (OCT) revealed subfoveal thickening and nodularity of the retinal pigment epithelium, with disruption of the adjacent photoreceptor inner segment–outer segment junction (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFluorescein angiography demonstrated late-staining hyperfluorescence (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). The fundus autofluorescence (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e) confirmed a more clearly delineated lesion, with distinct borders of hyperautofluorescence, and allowed better structural characterization.\u003c/p\u003e\u003cp\u003eSerologic testing subsequently confirmed the diagnosis of syphilis (serum TPHA 1:2560, FTA-ABS IgG 1:5120, RPR 1:128), and an evaluation for neurosyphilis was undertaken. Cerebrospinal fluid analysis revealed pleocytosis (23/µL, lymphocytic), reactive TPHA (1:256), FTA-ABS IgG (1:256), RPR (1:2), and an elevated ITpA index of 12.6. At that time, systemic penicillin therapy was initiated at a dose of 25\u0026nbsp;million IU per day intravenously for 14 days. Over the following weeks, the patient showed steady improvement in both episcleritis and visual acuity. All the materials and methods that are used to complete the study should be mentioned.\u003c/p\u003e"},{"header":"Discussions and Conclusions","content":"\u003cp\u003eSyphilis is a multisystem infectious disease caused by the spirochete \u003cem\u003eTreponema pallidum\u003c/em\u003e and remains a diagnostic challenge due to its protean clinical manifestations. Ocular syphilis, often referred to as the “great masquerade,” can involve nearly any ocular structure and may be the sole presenting feature of systemic infection. Because of its variable presentation, diagnosis may be delayed, particularly in patients without systemic symptoms or identifiable risk factors.\u003c/p\u003e\u003cp\u003eThe patient developed acute syphilitic posterior placoid chorioretinopathy (ASPPC), a distinctive manifestation characterized by large yellowish placoid lesions at the posterior pole [\u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e]. ASPPC commonly presents with outer retinal disruption on optical coherence tomography (OCT), as abnormalities of the retinal pigment epithelium and photoreceptor layers, which were consistent with this case. Inflammatory involvement of the choriocapillaris–retinal pigment epithelium–photoreceptor complex is usually revealed by fluorescein angiography that commonly demonstrates late staining or hyperfluorescence of the lesion [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e]. However, in this case study, the interpretation was limited by coexisting diabetic retinopathy and myopic fundus changes, which may have contributed to nonspecific hyperfluorescent patterns. To explain, coexisting diabetic retinopathy and myopic fundus changes can produce background microvascular leakage, window defects, and chorioretinal atrophy, reducing the diagnostic specificity of fluorescein angiography findings. Prompt recognition and treatment with systemic penicillin generally result in favourable anatomical and visual outcomes, as observed in our patient [\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eASPPC has been more frequently reported in immunocompromised individuals, particularly in association with human immunodeficiency virus (HIV) infection [\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, increasing reports in immunocompetent patients highlight that absence of immunosuppression does not preclude the diagnosis. In such individuals, clinical suspicion may be lower, contributing to delayed diagnosis.\u003c/p\u003e\u003cp\u003eA very important feature in this studied case is the initial presentation with isolated episcleritis which is typically regarded as benign and self-limited, later associating with acute syphilitic posterior placoid chorioretinopathy. Episcleritis is most often idiopathic and rarely associated with severe intraocular pathology [\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e]. In this patient, ipsilateral episcleritis persisted for several months prior to the development of posterior segment changes and the onset of visual decline. The patient’s early inflammation was most probably consistent with an initial manifestation of ocular syphilis. Systemic infectious causes, including syphilis, should be considered when episcleritis does not resolve as expected or when it is followed by new visual complaints.\u003c/p\u003e\u003cp\u003eAlthough episcleritis is often regarded as a benign and self-limited condition, this case demonstrates that what appears to be a simple episcleritis, particularly when accompanied with posterior segment inflammation, can reflect a more serious ocular complication.\u003c/p\u003e\u003cp\u003eIn this patient, the initial presentation of isolated episcleritis with no systemic symptoms, and preserved visual acuity contributed to a delay in diagnosis of ocular syphilis. The later development of acute syphilitic posterior placoid chorioretinopathy with progressive visual decrease demonstrates how inflammation that appears mild and limited to the anterior segment can sometimes precede posterior segment inflammation. For patients with persistent or unexplained episcleritis, early serologic testing and a careful examination of the posterior segment are advisable. In such cases, taking the time to revisit the patient’s history, especially looking for subtle systemic symptoms, can uncover valuable diagnostic clues. As ocular syphilis continues to re-emerge worldwide, ophthalmologists must remain alert in atypical or non-resolving cases of episcleritis, particularly when accompanied with posterior segment inflammation, to secure an accurate diagnosis and reduce the risk of permanent visual loss.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASPPC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcute Syphilitic Posterior Placoid Chorioretinopathy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBCVA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBest\u0026ndash;Corrected Visual Acuity\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFAF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFundus autofluorescence\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFTA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eABS\u0026ndash;Fluorescent Treponemal Antibody Absorption\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHIV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHuman Immunodeficiency Virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIU\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInternational Units\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOculus Dexter (Right Eye)\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOptical Coherence Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRPR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRapid Plasma Reagin\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTPHA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTreponema Pallidum Hemagglutination Assay\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWHO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWorld Health Organization\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics approval and consent to participate\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e\n\u003ch2\u003eAvailability of data and materials\u003c/h2\u003e\n\u003cp\u003eThe original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003ch2\u003eCompeting interest\u003c/h2\u003e\n\u003cp\u003eThe author declares no competing interests.\u003c/p\u003e\n\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eThe author has no acknowledgements to declare.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eNo funding was received for this study.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eYe Z, Yang M, Zou Y, et al. 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Ocular Syphilis and Human Immunodeficiency Virus Coinfection Among Syphilis Patients in North Carolina, 2014\u0026ndash;2016. Sex Transm Dis. 2019;46(2):80\u0026ndash;5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/OLQ.0000000000000910\u003c/span\u003e\u003cspan address=\"10.1097/OLQ.0000000000000910\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilhelmus KR, Yokoyama CM. Syphilitic Episcleritis and Scleritis. Am J Ophthalmol. 1987;104(6):595\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0002-9394(87)90170-X\u003c/span\u003e\u003cspan address=\"10.1016/0002-9394(87)90170-X\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNeri P, Pichi F. 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Ophthalmology. 1999;106(4):729\u0026ndash;31. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0161-6420(99)90157-4\u003c/span\u003e\u003cspan address=\"10.1016/S0161-6420(99)90157-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\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":"Syphilis, ocular syphilis, chorioretinopathy, episcleritis, Treponema pallidum","lastPublishedDoi":"10.21203/rs.3.rs-9254419/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9254419/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTo report the case of an immunocompetent 64-year-old man with acute syphilitic posterior placoid chorioretinitis with concurrent ipsilateral episcleritis.\u003c/p\u003e\u003ch2\u003eCase presentation:\u003c/h2\u003e \u003cp\u003eThe patient first came with sectoral redness in the right eye and was diagnosed with acute episcleritis. At that time, treatment was limited to artificial tears. About four months later, the patient returned because of persistent episcleritis in the right eye and the vision had noticeably worsened; visual acuity had declined from BCVA 20/32 to 20/80. In the view of this, topical prednisolone was initiated at a frequency of three times daily. Fundus examination of the posterior segment revealed a large yellowish placoid lesion involving the posterior pole. The clinical appearance was concerning for acute syphilitic posterior placoid chorioretinopathy (ASPPC). Multimodal imaging was subsequently performed. Fluorescein angiography interpretation was limited due to coexisting diabetic retinopathy and myopic fundus changes, which may have confounded the angiographic finding. Optical coherence tomography showed disruption of the outer retinal layers. Subsequent serologic testing confirmed syphilis, and the patient was evaluated for possible neurosyphilis. Treatment with systemic penicillin was initiated, after which both the episcleritis and visual acuity gradually improved.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eEpiscleritis that presents as an isolated red eye, in the absence of systemic symptoms or visual decrease, may represent an early manifestation of ocular syphilis in immunocompetent patient. Notably, the coexistence of episcleritis with placoid posterior chorioretinitis must raise prompt suspicion for syphilis. Early recognition of this association is crucial, given that delayed recognition may result in preventable, vision-threatening complications.\u003c/p\u003e","manuscriptTitle":"Episcleritis Preceding Acute Syphilitic Posterior Placoid Chorioretinopathy in an Immunocompetent Patient: A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-07 10:19:56","doi":"10.21203/rs.3.rs-9254419/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":"660a7e70-da9c-4b5b-8650-4014b1d07469","owner":[],"postedDate":"April 7th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-11T08:42:19+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-07T02:33:38+00:00","index":25,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T08:59:04+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-07 10:19:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9254419","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9254419","identity":"rs-9254419","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}