Neurosyphilis in a young adult: very early tertiary syphilis?

A rare episode of early neurosyphilis occurred in a 34-year-old, otherwise healthy, woman. Based on an isolated positive Borrelia burgdorferi serology (later interpreted as a cross-reaction), early ceftriaxone was initiated, in the suspect of Lyme borreliosis. Even after the diagnosis was corrected into that of a neurosyphilis, ceftriaxone administration was continued, until it achieved complete clinical and microbiological success after 24 days of treatment in a day-hospital setting, and three-weekly penicillin administrations. When considering the differential diagnosis, a luetic aetiology should not be underestimated when facing young patients with signs-symptoms of a meningoencephalitis. Our case report was characterized by an extremely low patient's age, compared with the occurrence of tertiary neurosyphilis, more than three years after the last sexual contacts. The diagnosis was confirmed by highly positive treponemal and non-treponemal serum and cerebrospinal fluid serology, and several suggestive clinical manifestations: seizures, altered mentation, cognitive impairment, lip drop, and anisochoria. These concomitant findings, together with a neuroradiological report indicating a diffuse meningoencephalitis, allowed us to confirm the diagnosis of neurosyphilis, together with a demonstrated cross-reaction of B. burgdorferi serology. Although ceftriaxone benefits from its once-daily administration (and can be easily delivered on outpatient basis), it is not the firstline treatment of neurosyphilis. However, our experience demonstrated a favourable and rapid response to ceftriaxone, in the absence of toxicity and disease sequelae.