You have asked this question before, essentially.
People don't get syphilis sores on their hands. They get them orally or genitally. Kissing someone on their hands is not a risk.
Perhaps if you are so afraid of syphilis, you should avoid sexual contact until you know someone well enough to get tested with them. That's a reasonable request for couples.
Also, syphilis isn't that common. You are living in fear needlessly. Please get some counseling. You seem to have a real anxiety issue. I say that with compassion, not criticism.