Acute Syphilitic Posterior Placoid Chorioretinitis in an immunocompetent individual: A case report

Background: Acute Syphilitic Posterior Placoid Chorioretinitis (ASPPC) is a rare but characteristic manifestation of ocular syphilis. It typically presents with yellowish placoid lesions over the macula due to inflammation involving the outer retina and retinal pigment epithelium (RPE), secondary to choroidal infiltration by Treponema pallidum antigens. ASPPC is commonly reported in immunocompromised individuals, particularly those with HIV co-infection, and can mimic other posterior uveitic conditions, making early diagnosis challenging but crucial. Case Presentation: We report a case of a 35-year-old immunocompetent male who presented with painless, progressive blurring of vision in the left eye over two months. Fundus examination revealed faint placoid lesions at the macula, vitritis, hyperemic optic disc, and inferior vasculitis. Although bilateral involvement was noted, findings were more prominent in one eye. The patient had a recent history of palmar rash and high-risk sexual behavior. Multimodal imaging, including spectral domain optical coherence tomography (SD-OCT), demonstrated outer retinal disruption with loss of the ellipsoid zone and external limiting membrane. Fundus autofluorescence (FAF) and fluorescein angiography (FFA) showed typical features consistent with ASPPC. Serological tests confirmed syphilis with a positive RPR and TPPA, while HIV testing was negative. The patient responded well to systemic antibiotic therapy, with resolution of symptoms and no recurrence noted. Conclusion: This case emphasized the importance of considering ASPPC in the differential diagnosis of posterior uveitis, even in immunocompetent individuals. Prompt recognition, aided by multimodal imaging and serology, enables early treatment and prevents irreversible visual loss or recurrence.