I noticed the old question (8109) was still open, but following up here as I already had my 2 follow ups. 

I would love for your comments on the following items:

1. I got a second syphilis test at 38 days, negative too (1st neg at 29 days). I have read about conclusive syphilis at 12 weeks and am still nervous. Other sources say 6. Is my latest test (5.5 weeks) conclusive. 

2. About the white lesion described in the original thread 3rd question. Does a chancre pop? I was able to squeeze it and has remained only a single black point (I suppose a small scar of less than 1mm, looks exactly like a pore wide) after the fact. 

3. On top of that, is 35 days too late for syphilis? 

4. If this were an infectious lesion, would I have gotten positive RPR by then? (4 days after finding it). These questions purpose is to educate me so hopefully I don't immediately freak out next time something shows up (I never had any kind of bump before in penis). 

5. Are whiteheads actually possible to appear on shaft, where no hair grows? 

6. Am I right to think absolutely zero HIV risk for this and mutual masturbation exposures? Aka. No need to worry about unprotected sex with stable partner? 

7. Finally, just for my own sake, can a Syphilis test be conclusive before chancre appears. Concretely, I have heard it can take up to 90 days for chancre to appear, let's say a test is taken at 6 weeks for a syphilis case where chancre would show up at 90 days, will the test still be positive? 

How is syphilis actually spread? As in how easy is for an exposure to result in transmission? Should friction be present? Is just touching a lesion enough for transmission (ie let's say genitals touch while kissing)? Basically, I try to understand when I don't need to worry. 

1,3,4. Almost all syphilis infections would have given obvious symptoms:  that you have not developed a visible open sore (chancre) on your penis within 2-3 weeks is strong evidence you didn't catch syphilis; 35 days would be too long. Combined with the negative blood test at nearly 6 weeks, you can be sure you don't have it. However, for absolutely conclusive evidence, I agree a final blood test at 3 months would make sense. 

2,5. Chancres do not behave this way. They are open sores. Sounds like you had a pimple, nothing more. And yes, pimples (white heads) are not rare on the penile shaft. (You don't need hair follicles to develop pimples.)

6. Nobody in the world has ever been known to catch HIV by hand-genital contact.  You won't be the first. (Same for syphilis, by the way.)

7. I have never heard of a chancre developing as late as 90 days after exposure. And I've also never known the RPR to be positive prior to appearance of a chancre.

Please believe you were at little or no risk for either syphilis or HIV. Combining the low risk plus the negative tests, you can be sure you weren't infected. If somehow I were in your situation, I would have no more testing and would be continuing unprotected sex with my wife without worry.

I hope these comments are helpful--   HHH, MD