I've asked something a bit similar before, but that was a few weeks ago and I wanna just confirm this for the peace of mind...
So I had a red lump on the inside of my foreskin, just right to the frenulum 3 weeks ago. It was about 5 mm x 4 mm big, bright red at first (at least as I saw it at night then) and then became sorta whitish or pale yellowish in colour with red surrounding tissues. The whole thing is flat or at most slightly raised, and kind of looks like a blister with some pus in it. It's soft, not painful on it's own but painful when pressed gently. I went to a doctor but was too embarrassed to say that I had unprotected oral sex with a girl (who said she has never had any oral lesion like syphilis, or herpes, for that matter) around 3.5 months ago (from now, 3 months from the appearance of the red thingy)... The doc then said it was just bacterial infection of the foreskin due to poor hygiene and gave me 100 mg doxycycline twice per day for 7 days, and topical chloramphenicol. After the first dose of cream and doxycycline the lump somehow burst, and there was some bleeding and a little bit of whitish pus in the next morning. The bleeding subsided quickly, typical of mucosal lesions, and the lump (now flat) kinda looked like a flaccid, drained blister but remained red. The bleeding occurred for two more mornings. I stopped chloramphenicol after around 5 days, when the lump has been reduced to a small whitish spot. The lump later (after I think 5 to 6 days) returned, and i started to put the cream on again. It went away again after around 3 days, during which it ruptured and was painful when I urinated, as there was some bleeding especially when I accidentally rub it. Two little pieces of skin fell off, somewhat like the canker sores when you remove the outermost layer of tissue, revealing some raw skin underneath. The lesions healed on its own without scab formation after around one day and has been asymptomatic so far.
Also, around 3 days after the lump appeared, I was diagnosed of strep throat and was put on levofloxacin for 5 days.
I never noted any hardening of the lesions or a "red, slightly raised rim creating a crater shape" characteristic of syphilis chancres. But I've been super worried about syphilis because it takes on so many different forms and my lesion actually looks quite similar to this picture here (http://www.linkbeaver.com/wp-content/uploads/import/2016/03/28/10/96f59-herpes+on+uncircumcised_121485.jpg), except that it is smaller in size and there was no red, raised border. It looks more like this one here actually: http://www.vividmagazine.net/wp-content/uploads/2015/01/how-to-heal-a-canker-sore-fast-1024x997.jpg , except that it's on my foreskin. At some point during healing it definitely looked like a pimple but again, I'm not sure.There's no lymph node enlargement in the groin so far, and I guess the cervical and clavicular ones are just due to strep throat. Plus, I guess if it is syphilitic chancre it wouldn't go away in a few days, return briefly and then get eradicated within a few days again? Also, I read from my pathology textbook (yes I'm a medical student) that syphilis involves epithelial damage, which didn't seem so this time, since the peeling skin looks and feels more like keratin, and the skin underneath is pretty much intact.
Any thoughts? I hope it's not syphilis? Please.