62–year–old man with AIDS presented with a history of photophobia and blurry vision in his left eye. He denied any pain, discharge, redness or floaters. There was no associated change in mental status, fever, headache, neck stiffness, or nausea. One and a half years ago he had blurry vision in both eyes and was diagnosed with anterior uveitis secondary to neurosyphilis, for which he completed a full course of treatment. He reports compliance with his HAART regimen and abstinence from sexual activity. Physical exam included normal vital signs. Pupils were reactive to light and accommodation. Slit lamp exam revealed cells and flare in the anterior chamber of the left eye, and visual acuity was 20/60. The remainder of his exam was normal.
Syphilis, an infection caused by the spirochete Treponema pallidum, results in systemic, chronic inflammation. In 1999 there were an estimated 11.76 million new cases of syphilis in the adult population. It is mainly contracted through sexual contact, but other modes of transmission include vertical transmission, blood transfusion, or organ transplant. Neurosyphilis can occur during any of the four stages of syphilis. Although there are asymptomatic individuals, symptoms associated include tabes dorsalis, seizure, stroke, meningitis, or altered mental status. Ocular manifestations, include uveitis, neuroretinitis, or optic neuritis. While a reactive CSF–VDRL diagnoses neurosyphilis, a nonreactive test does not exclude it. In non–HIV infected patients with suspected neurosyphilis who do not have a reactive test, a CSF lymphocyte count >5 cells/mL or a protein concentration >45 mg/dL is consistent with the diagnosis. Because the CSF leukocyte count usually is elevated In patients with HIV, using a higher cutoff (>20 cells/mL) improves the specificity of the diagnosis. Additional evaluation using FTA–ABS testing on CSF can be considered with a nonreactive CSF–VDRL; neurosyphilis is highly unlikely with a negative CSF FTA–ABS test. The treatment of choice for neurosyphilis is aqueous crystalline Penicillin G 3–4 million units IV q4 hours or continuous infusion for 10–14 days.
The patient experienced recurrence of anterior uveitis, raising concern for relapsing neurosyphilis, which has been previously shown to relapse in patients who are co–infected with HIV. A literature review of syphilitic uveitis cases yielded 143 patients from 1984 to 2008.4 Of the thirteen patients requiring re–treatment, eleven were co–infected with HIV and eleven had previously been treated with IV Penicillin G. Of these 143 patients, 65% were co–infected with HIV; moreover, 96% of patients with isolated anterior uveitis also had a diagnosis of HIV.4 It is important for the hospitalist to recognize that patients co–infected with HIV can have relapse of syphilis despite treatment, and that these patients should be carefully monitored in the outpatient setting.