A 32-year-old man with a painless genital ulcer has the following syphilis serology: VDRL reactive (1:64 titer), TPHA reactive, FTA-ABS reactive. He has no prior syphilis history. The most appropriate management is:

• A Penicillin G benzathine 2.4 MU IM weekly for 3 doses (late latent syphilis treatment)
• B Penicillin G benzathine 2.4 MU IM single dose (primary/secondary syphilis treatment) ✓
• C Doxycycline 100 mg twice daily for 14 days (alternative for penicillin allergy)
• D Observation only — this is biologically false positive VDRL

Explanation

The clinical picture of a painless genital ulcer (chancre) with reactive non-treponemal (VDRL 1:64) and treponemal tests (TPHA, FTA-ABS) confirms primary syphilis. Primary and secondary syphilis are treated with a single dose of benzathine penicillin G 2.4 million units IM. Three weekly doses are reserved for late latent syphilis or syphilis of unknown duration. A biologically false positive VDRL would show TPHA/FTA-ABS negative; here both treponemal tests are reactive, confirming true infection requiring treatment.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.