Any Help?
What age are you ? There can be various things that can cause these - from actual pimples, as you suggest, your other suggestion of an ingrown hair is close to other possibilities, such as a blocked or irritated skin pore. I ask you age because it could be something like a Fordyce Spot that is only forming when there is sufficient irritation going on in the area - most irritation in this area of the shaft of the penis is caused by friction due to masturbation, and linked to this, and the normal functioning of the skin in the area is whether you apply anything as a lube when you masturbate. This could be an actual Lube, or skin cream or lotion or something like Baby Oil or Lotion .....
Im 21 yo, fortunately, it appears that the thing is almost disappearing... i was so scared...
... thanks for the update ....