Neurosyphilis results from infection of the brain, meninges or spinal cord by the spirochete Treponema pallidum and comprises a wide spectrum of clinical and pathological features including psychiatric symptoms. We report the case of a patient who presented with psychotic symptoms and was diagnosed with late syphilis.

A 45-year-old male with anxiety, insomnia, auditory hallucinations, delusions of persecution and mild cognitive impairment of relative recent onset was admitted to the Department of Skin and Venereal Diseases because of serological evidence of syphilis (TPHA 1:320). Upon admission treatment with olanzapine (15 mg/d) was started. Further evaluation yielded positive syphilis serology (TPHA, RPR and FTA-abs) in serum, slight cerebral atrophy in CT and discrete aneurysmatous dilatation of the aortic arch by heart ultrasonography. CSF findings did not satisfy laboratory criteria for the confirmation of diagnosis of active neurosyphilis. Late (tertiary) syphilis with beginning cardiovascular involvement was diagnosed and treatment with benzathin penicillin was administered. Six months later he was readmitted for a follow-up examination. Psychiatric symptoms were improved.

Although quite rare today, neurosyphilis should be considered in the differential diagnosis of patients with psychotic symptoms and positive syphilis serology, as the appropriate treatment depends on early and accurate diagnosis. Moreover, given the wide use of antibiotics, abortive cases of neurosyphilis with atypical presentation forms must also be considered. Finally, this case suggests that in addition to the appropriate antibiosis, treatment with antipsychotics seems to be effective in controlling psychiatric symptoms emerging in the course of late syphilis.