Does a low serofast RPR titer (such as 1:1 or 1:2) in the setting of a remote history of appropriately treated latent syphilis in a patient with now uveitis of yet unknown etiology referred from ophthalmology for possible ocular syphilis make a diagnosis of ocular syphilis less likely?

I err on the side of offering empiric treatment. As syphilis rates have risen over the past 20 years, so has the incidence of syphilitic uveitis (Mir et al., PMID 37991790), and the question posed, therefore, represents a not uncommonly encountered conundrum for infectious disease consultants. Syphilitic uveitis has been described at all stages of syphilis (except primary), so while we frequently see patients presenting when they have active/infectious syphilis with a higher non-treponemal titer, the titer can be low as described in this case and doesn't rule out the possibility of syphilis (Lee et al., PMID 26297110). It would be less likely to occur as a late complication of a previously treated person, but there are treatment failures, a...