Chapter 124. Sexually Transmitted Infections: Overview and Clinical Approach (Part 18) Table 124-8 Initial Management of Genital or Perianal Ulcer Usual causes Herpes simplex virus (HSV) Treponema pallidum (primary syphilis) Haemophilus ducreyi (chancroid) Usual initial laboratory evaluation Dark-field exam, direct FA, or PCR for T. pallidum; RPR or VDRL test for syphilis (if negative but primary syphilis suspected, repeat in 1 week); culture, direct FA, ELISA, or PCR for HSV; consider HSV-2-specific serology. In chancroid-endemic area: PCR or culture for H. ducreyi Initial Treatment Herpes confirmed or suspected (history or sign of vesicles): Treat for genital herpes with acyclovir, valacyclovir, or famciclovir Syphilis confirmed (dark-field, FA, or PCR showing T. pallidum,.
