Acute syphilitic posterior placoid chorioretinopathy: An infectious or autoimmune disease?

PURPOSE: To report a case of acute syphilitic posterior placoid chorioretinopathy (ASPPC) that demonstrated partial resolution with immunosuppressive therapy secondary to a misdiagnosis as Behçet's disease followed by a relapse which was successfully treated with the appropriate treatment. OBSERVATIONS: A 34-year-old female patient presented to our service with complaints of decreased vision in the left eye (OS). She initially developed similar symptoms seven months prior to presentation and was diagnosed as Behçet's disease based on the clinical picture of papillitis, vasculitis and placoid chorioretinitis in the posterior pole of OS. She was started on daily oral prednisone 60 mg and weekly methotrexate 10mg by her rheumatologist. The patient's ocular symptoms improved one month prior to presentation with resolution of the placoid lesion but persistence of vasculitis and papillitis. At that time, the dose of the prednisone was decreased to 30 mg which resulted in a relapse of the placoid chorioretinal lesions and worsened visual acuity at the time of presentation to us. Extensive laboratory workup demonstrated positive serology for syphilis. A diagnosis of syphilitic placoid chorioretinitis was made and the patient was treated with intravenous penicillin G for 2 weeks. The vitritis, papillitis, and placoid chorioretinitis resolved along with improvement in vision following the treatment. CONCLUSIONS AND IMPORTANCE: Ocular findings in syphilis are heterogeneous and may mimic variety of ocular diseases. ASPPC is a rare ocular manifestation of syphilis and its natural course and underlying pathophysiology is not well understood. However, irrespective of the underlying mechanism of the disease, all patients with ASPPC should receive treatment to prevent recurrence and long-term functional damage.