A 34-year-old man presents to the ophthalmology clinic with a 3-day history of redness, photophobia, and blurred vision in his left eye. He also reports a generalized rash on his palms and soles that appeared two weeks ago. On physical examination, slit-lamp biomicroscopy of the left eye reveals fine keratic precipitates on the corneal endothelium and 3+ cells and flare in the anterior chamber. Dilated funduscopic examination shows hazy vitreous and several yellowish-white placoid lesions in the macula and mid-periphery. A rapid plasma reagin (RPR) test is reactive with a titer of 1:128.
Which of the following is the most appropriate next step in the management of this patient?
The correct answer is:
C) Intravenous penicillin G
This patient presents with signs of secondary syphilis with a palmar and plantar rash and ocular involvement. Ocular syphilis can manifest in almost any part of the eye, but uveitis is the most common presentation. The presence of placoid lesions suggests acute syphilitic posterior placoid chorioretinitis, a highly suggestive finding for syphilis. Any patient with ocular syphilis must be managed as having neurosyphilis, regardless of whether they have other neurological symptoms or a positive lumbar puncture. Therefore, the treatment of choice is aqueous crystalline penicillin G for 10–14 days.
Answer choice A: Intramuscular benzathine penicillin G, is incorrect. While this is the standard treatment for primary, secondary, or early latent syphilis without neurological or ocular involvement, it does not achieve adequate cerebrospinal fluid or intraocular concentrations to treat ocular syphilis.
Answer choice B: Intravenous ceftriaxone, is incorrect. While ceftriaxone can be used as an alternative for neurosyphilis in patients with penicillin allergies, intravenous penicillin G remains the first-line, gold-standard therapy for neurosyphilis/ocular syphilis.
Answer choice D: Intravitreal foscarnet, is incorrect. This is an antiviral medication used for viral retinitis, such as acute retinal necrosis (ARN) or cytomegalovirus (CMV) retinitis. While the placoid lesions of syphilis can sometimes mimic viral retinitis, the positive RPR and rash on the palms and soles point to syphilis.
Answer choice E: Topical prednisolone and atropine, is incorrect. While topical steroids and cycloplegics are used to manage the inflammation and pain of anterior uveitis, they are adjunctive treatments. They do not treat the underlying Treponema pallidum infection and would be insufficient as a next step without systemic antibiotics.
Key Learning Point
Ocular syphilis can occur at any stage of the infection and is functionally equivalent to neurosyphilis. Any ocular involvement (uveitis, optic neuritis, retinal vasculitis) requires treatment with the neurosyphilis regimen of 10–14 days of intravenous aqueous crystalline penicillin G.
