You are correct. Primary syphilis was confirmed by the combination of a positive enzyme immunoassay for IgM, raised venereal dz research laboratory titer, unilateral painless cervical lymphadenopathy, and a perioral lesion w/ a plasma cell-rich infiltrate. PCR swabs from a lesion can be used to distinguish herpes and syphilis. Primary screening for syphilis by serological testing is also recommended. If these tests are negative, bx should be used to look for further evidence of syphilis or malignancy. This pt was treated w/ IM benzathine PCN and underwent screening for other sexually transmitted infections. He also received long-term follow-up.

BMJ 2017;358:j3823