When should lumbar punctures be done in patients with syphilis?

Lumbar punctures to rule out neurosyphilis are recommended for patients with late latent syphilis of more than 1-year duration or unknown duration who demonstrate neurologic symptoms, treatment failure, serum nontreponemal antibody titer equal to or greater than 1:32, other evidence of active syphilis (iritis, aortitis, gumma), nonpenicillin treatment, or positive HIV test. Syphilis frequently attacks the central nervous system, as demonstrated by the fact that 40% of patients with primary or secondary syphilis demonstrate cerebrospinal fluid pleocytosis, and 24% of patients with secondary syphilis demonstrate a reactive VDRL. In patients with syphilis/HIV coinfection there is evidence to suggest that lumbar puncture may be indicated in all coinfected patients since the disease is more aggressive; however, this is also controversial.

Chan DJ: Syphilis and HIV co-infection: when is lumbar puncture indicated? Curr HIV Res 3:95–98, 2005.