Welcome to the forum.
Neither syphilis nor any other STDs are transmitted by hand-genital contact or by exposure to saliva. You are not at risk.
Best wishes-- HHH, MD
Dear Doctor,
This evening I just noticed something very similar to a pimple on on the skin covering the penis, 0,2 0,3 mm. I am sure i had nothing more than described with the girl. What I have to do? I am very worried thanks
"I am sure i had nothing more than described with the girl." I agree.
Therefore, I don't know why you are "very worried"!!!
Syphilis is not likely to cause a pimple anyway. However, herpes can do that -- although if you have genital herpes, you can safely assume you had it before the exposure mentioned above.
"What I have to do?" That's easy, and I think very obvious: visit a doctor or clinic.
I'll be happy to comment once again if you would like to return to let me know the results after you have been professionally evaluated.