Rash / goosebumps on the penis
I have a question that hopefully can get answered here.
Quite some time ago I noticed that from time to time I get what looks like a rash on the tip of my penis. It never hurts, but it just looks odd to me. Just recently I've been to a STD clinic and got tested, but all the test came back negative and showed that I haven't contracted an STD. So I'm wondering if anyone here (provided you're a doctor) can tell me what this is or if anyone has/had the same problem.
I don't know if this is of any help, but the doctor that I saw put me on this antibiotic called "Ciprofloxacin" and I'm wondering if maybe this is a condition due to the taking of this medication. Any help will be greatly appreciated. I would have asked the doctor that I'm seeing, but he's not in his office tomorrow and it's Labor Day weekend and I was afraid of not getting an answer until 5 days from now.
Again, thank you in advance.