Syphilis: keeping an eye out for the great mimic.

A 27-year-old woman presented to her optometrist with a 2-week history of improving vision, such that she no longer required corrective lenses. She also had chronic daily headache and pulsatile tinnitus that worsened when lying flat. Direct funduscopy identified bilateral severe optic disc oedema (Frisen grade 4–5) (figure 1). Uncorrected visual acuity was normal bilaterally (prescription 3 years before: OD –2.25D; OS –2.00D). Visual field testing showed mild enlargement of the right eye blind spot only. MR scan of brain showed prominent subarachnoid spaces around the optic nerves with flattening of the posterior poles (figure 2). MR cerebral venogram was normal. Cerebrospinal fluid (CSF) opening pressure was elevated (34 cmH20) and analysis showed a mild pleocytosis with white cell …