###Human: How to treat canker sores with pus in them? ###Assistant: Hello. I have been through your query and I can understand your concern. Canker sores are a characteristic feature of syphilis. This syphilis is a sexually transmitted disease. Purulent pustules are generally seen which burst to form canker sores. You should get yourself tested for the syphilis infection as soon as possible because syphilis should be treated immediately. Otherwise, it can lead to some of the serious complications to the brain, heart, nervous system, etc. However, you do not need to worry as once detected it can be completely eradicated from the body. I would advise you to have a visit to your nearest dentist and also make an appointment with the general physician for eliminating any other cause for the same. If you were my patient, after detailed drug history, I would have prescribed you antibiotics like Penicillin and topical analgesics (if the pain is in the sores) for the infection elimination. I would also advise you to adhere to not having sex during this period as it can spread through having sex. I would also advise you to have good oral hygiene and brush your teeth twice daily and floss regularly.