Neurosyphilis in a suspected case of giant cell arteritis

A 67-year-old man had a few month history of deteriorating visual acuity. He had originally presented to ophthalmology with right-sided visual blurring. This subsequently progressed to involve the left eye. At this point, he was empirically treated with high-dose glucocorticoids, both orally and intravenously, with the suspicion that giant cell arteritis was causing acute visual deterioration of his left eye. Unfortunately, his symptoms did not improve. During an admission to hospital for a pneumonia, he underwent further investigations for this bilateral visual loss. He was diagnosed with left neuroretinitis and right vitritis. A thorough workup revealed positive syphilis serology and cerebrospinal fluid was positive on venereal disease research laboratory testing. He was diagnosed and treated for neurosyphilis with intravenous benzylpenicillin 4 million units 4 hourly for 14 days. His left-sided vision improved but he still suffers from severe visual impairment in his right eye.