Neurosyphilis: A rare cause of encephalitis in a young male.

Acute neurosyphilis is a rare but easily treatable cause of subacute confusion. Its clinical presentation is varied, with reported phenotypes ranging from acute stroke-like presentations to psychosis, dementia and meningoencephalitis. Neurosyphilis is easily detectable and treatable, despite its clinical heterogeneity. We present a 45-year-old man without HIV presenting with a subacute encephalitis, with cerebrospinal fluid and blood markers strongly positive for syphilis, with clinical improvement following 2 weeks of empirical intravenous antibiotic therapy.