Nonetheless, he should be checked by a blood test, since perhaps it was he who infected you at the beginning of your relationship. Women are often unaware of having a chancre, since it can be deep in the vagina, and they may ignore the rash of the secondary stage since it goes away by itself. So it's pretty common to diagnose syphilis in a woman who denies ever having had the first two stages of the disease. Someone who is diagnosed during the long period between the secondary and tertiary stages is said to have late latent syphilis. Treatment of late latent syphilis consists of three injections of long acting penicillin one week apart, if the person is not allergic to penicillin.
Some experts recommend doing a lumbar puncture to test the cerebrospinal fluid.
If this is positive, it indicates that the person has neurosyphilis, that is infection of the brain or spinal cord, and more extensive treatment is required. The Centers for Disease Control and Prevention, in the Guidelines for Treatment of Sexually Transmitted Diseases , does not recommend a lumbar puncture for everyone, but says it must be done if there are any signs of neurosyphilis, or other forms of tertiary syphilis, or if the person is HIV positive, since treatment in such cases is more difficult. Everyone who tests positive for syphilis should be tested for HIV , including you, even if you have never had any other STDs. HIV infection is easily transmitted when there is an open sore in the genitals, and although you probably never noticed such a sore, you almost certainly had one, and that would have increased your risk of getting it. This is one doctor who makes housecalls.