Acyclovir Ointment Does Not Affect the Dark-field Examination in Primary Syphilis

In the cases of two patients and in a rabbit with experimental syphilis, treatment of primary syphilis lesions with 5% acyclovir ointment did not affect detection of Treponema pallidum by dark-field microscopy. These results indicate that the dark-field examination need not be delayed in patients whose genital ulcers have been treated with acyclovir ointment.