hard pimple on penis

[mk73]

Hello.  Three days ago i noticed on the shaft of my penis (about 1.5 inches above my scrotum) what look like a pimple.  Its about 2 millimeters wide and feels solid.  Almost feels as though there is a small pebble on the skin of my penis.  It doesn't bother me and I don't have any other symptoms but it is sensitive and slightly hurts if i press against it.  I recently had sex with 2 different female friends about 2 weeks ago but was protected both times.  I did shave in that area recently and thought maybe it might be irritation but when i examined closely i noticed the pimple didn't have  a hole where i could pop something out.  It just feels like something has grown in the area.  I did a lot of research to try to find pictures of something it looks like on the internet but did not find anything.  I was diagnosed with molloscum a few years ago but this looks and feels totally different then what I had in the past.  This is much wider and raised  higher.  It is also  sensitive to touch.  Also its not really a different color either except when i keep touching it.  Any ideas would be real helpful.

[Edward W Hook, MD]

Shaving might lead to cyst/folliculitis formation.  It would not be a site for introduction of an STD.  Like I said, see a dermatologist.  EWH

[mk73]

Dr i just wanted to mention one more thing.  You said that it may of been caused by shaving.  Could shaving still be contributed to formation of a cyst if it appeared 10 days after I shaved?  Also can it still be a cyst if the pimple is redder the the surrounding skin?  Its not sensitive to touch anymore but it is still feels hard.  Im staring to think that i may of gotten infected by an std in an area where a condom might not have covered me fully during sex.     This pimple began to appear 3 days after my last sexual encounter.  

[Edward W Hook, MD]

No not always. They can persist for long periods of time. sometimes if they are troublesome a dermatologist will excise them.  EWH

[mk73]

but do these cysts go away. And how long does it take to go away on average?

[Edward W Hook, MD]

What you describe is most consistent with what dermatologist sometimes call a "simple cyst".  These fit the description and are totally benign;   shaving in the area may have contributed to its appearance..  Alternatively, you pay have an atypical case of molluscum, appearances aside or a wart.  Each of the latter two possibilities is lower on my list of candidates that the cyst.  My advice would be to seek the opinion of a dermatologist or experienced clinician, not because I think it is a problem but to satisfy your curiosity. It is almost certainly not something to worry about.  EWH