Garden-variety pimples certain can appear on the
penisCancer - penis
Curvature of the penis
Penis care (uncircumcised)
Penis pain and it sounds like that's what you had. The only STD that could possibly cause anything like that is herpes. Warts are solid tissue, do not develop white
headsHead and face reconstruction
Head injury
Head lice
Indications of head injury
Radial head injury, and cannot be popped.
Herpes usually starts with several blister-like lesions, not a single lesion. Also, herpes sores tend to be quite superficial. If it looked like a typical pimple, I see no worries here. However, no distant online expert can make a definite diagnosis. If you think you have been at risk for genital herpes and want to be certain, see a heatlh care provider (very soon, before the lesion heals). Your local health department STD clinic would be a good choice.
Best wishes-- HHH, MD
However, I did have one additional question. Regarding genital herpes, is there any defining characteristics that would seperate it from a common pimple? In general what would be a tell tale sign of herpes vs. a pimple.
Thanks.
None of this is hard and fast. But from all you say, you can be pretty sure you had a pimple, not herpes. However, if you need more definite information that this, you will have to see a doctor or clinic in person. You're never going to know for sure by asking questions on this forum or by any searching online.