Hey @AlexUobby that's a fordyce spot, us guys have a few of those in that state at any one time. I don't recommend it, but that is a small pus ball that will roll out if you try hard enough- as I said I wouldn't do that, it will be like that for a few weeks and fade, or potentially release its contents largely of its own accord.

And I don't really think that it is Folliculitis. I use a microscope to look at it, and I don't see any hair comes out of it. 

@WilsoInAusI have a very emergency update here.  Yesterday I noticed a small cut-like area at the end of my penis is a little red.  But today when I see it again, I see  a single tiny yellow blister. And I think the area is out of the protection zone of condom. My doctor lives 30 km away from me, and he won't work until Monday.  I don't know what to do

I know you can order it on line but how did you get it administered in US?