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

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.