A chancre is the sore that develops on your genitals or mouth in the early stages of syphilis, whereas a cold sore primarily appears around the lips and is caused by oral herpes. Both chancres and cold sores are caused by contagious sexually transmitted infections (STIs), but the STIs are very different. Syphilis is a bacterial infection that can be cured but has serious health consequences if it goes untreated; oral herpes is caused by a common viral infection that cannot be cured but can be managed with medication.
Syphilis spreads when you come in contact with a chancre during oral, vaginal, or anal sex. Herpes can be spread through kissing, oral sex and nonsexual activity such as sharing razors or towels.
You can often tell the difference between these two sores by their symptoms and appearance. A cold sore is:
- Located on the lips, mouth, and gums
- A blister that oozes fluid, then crusts over as it heals
A chancre is:
- Located primarily on the genitals, but can sometimes appear around the anus, lips, and mouth
- Hard and round
Both sores can appear as a single lesion or in clusters. Getting tested can confirm which infection you have.
Treatment and Prognosis
While cold sores will heal on their own within a week or two, once you’re infected with the herpes simplex virus you carry it for life. Your healthcare provider can, however, provide you with a medicated ointment to relieve the painful symptoms or an antiviral to reduce outbreak frequency and severity.
Chancres last three to six weeks and, because they’re often painless, can go unnoticed. Unlike oral herpes, syphilis is treatable at this stage but it’s important that you get tested and treated promptly. Your medical provider can prescribe you with an antibiotic that will clear the infection and prevent syphilis from moving into its more serious second phase.