Primary Syphilis

The distinguishing feature of primary syphilis is a painless ulcer on the vulva, vagina or cervix.

The ulcer:

• Is non-tender.
• Has a well-defined border.
• Has a smooth base.
• Starts as a macular lesion, forms a central papule, then erodes to form an ulcer crater.
• Is associated with enlarged, firm, mobile, non-tender regional lymph nodes.

Examination of surface scrapings of  lesion under darkfield microscopy will show the typical spirochetes. Serologic test for syphilis (VDRL, RPR) will be positive.

Optimal treatment is:

• Benzathine penicillin G 2.4 million units IM in a single dose

But for those allergic to penicillin, you may substitute:

• Doxycycline 100 mg orally twice a day for 2 weeks, or
• Tetracycline 500 mg orally four times a day for 2 weeks.
• Ceftriaxone 1 gram daily either IM or IV for 8--10 days (possibly effective).
• Azithromycin 2 grams PO once (possibly effective).

If the patient is pregnant, tetracyclines should not be used. Should the pregnant patient also be allergic to penicillin, desensitization is recommended by many, but circumstances may not allow for that. Of primary importance is that sufficient antibiotic gets across the placenta and to the fetus. If not, fetal syphilis will be insufficiently treated.

Within 24 hours of treatment, you may observe the Jarisch-Herxheimer reaction in patients. This reaction consists of fever, muscle aches and headache and may be improved by concurrent treatment with antipyretic medication.

Both the patient and her sexual partner(s) need treatment. Otherwise, she will be re-infected, even if the initial treatment is successful. Further, syphilis, untreated, ultimately can lead to permanent neurologic injury and death, so full treatment of all sexual partners is very important.

Long term followup is needed to make sure that the syphilis is completely gone from the patient and her sexual partner(s). The means to do that is complicated and current CDC recommendations are best followed.

CDC Treatment Guidelines