How do you manage a patient whose RPR fails to decline fourfold within 12 months after appropriate treatment for early syphilis?

The response depends on information not provided, such as the certainty of the diagnosis of "early" syphilis, including the actual stage (primary, secondary, early latent, and, if asymptomatic, the certainty of early versus late syphilis); details of the "appropriate" treatment already given; initia...