Late syphilis, latent

This code represents a stage of syphilis where there are no visible signs or symptoms of the disease, but serologic tests for syphilis are reactive. It indicates that the infection has been present for more than one year (or an unknown duration) since the initial infection. The disease remains in the body and can still cause damage to internal organs over time if left untreated.

Use this code when a patient has a documented history of syphilis with positive serological tests (e.g., RPR, VDRL, FTA-ABS) but no clinical manifestations of primary, secondary, or tertiary syphilis are present. This diagnosis is typically made when the duration of infection is unknown or known to be greater than 12 months. Documentation should clearly state "late latent syphilis" or "latent syphilis of unknown duration."

• Do not use this code if there are any clinical manifestations of tertiary syphilis (e.g., cardiovascular, neurosyphilis, gummas); instead, use a more specific code from A52.0-A52.7.
• Distinguish carefully from "early latent syphilis" (A51.5), which applies when the infection has been present for less than one year.
• Always ensure supporting documentation clearly specifies the latent stage and, if possible, the duration or unknown duration of the infection.