Acute syphilitic optic neuritis.
Two patients experienced acute unilateral visual loss as a manifestation of early infectious (secondary) neurosyphilis. In both cases, optic disc swelling was preceded by the development of a characteristic rash accompanied by mild signs of meningeal inflammation. Other signs of ocular inflammation, such as uveitis or retinal vasculitis, were absent. Optic neuritis may occur as a manifestation of the meningeal inflammation that can accompany secondary syphilis. In such patients, it is important to confirm involvement of the CNS and to institute appropriate antibiotic therapy.