I have a normal looking pimple on the shaft of my penis. I am also UN-circumsized. It has been there for 3 days. I'm 15, i have never had oral sex or intercourse, so I am pretty sure its not an STD. Is it normal to get a pimple on your penis!??!
I really don't see why not. Pimples seem to pop up in all sorts of places including in the hair, on the but etc.
Try dealing with it like a normal pimple. If it has a white head on it maybe get a tissue with a bit of tea tree oil or any antiseptic on it and clean it. Then leave it. You may have to wear slighly looser undies and check that they are cotton if this happens more often. Also jeans can be too tight and cause a warm sweaty area which is might give rise to a rash or a pimple. I doubt if your uncircumcision has any bearing except that you need to be normally hygienic.
A little talc puffed around the area after showers may also help you.