What Are These Red Dots (blotch) On Head Of My Penis?

After masturbation and the occassional bath, i notice that the head of my penis becomes somewhat covered in red blotches. the head is not fully covered. all that appears are these red dots over the head, they are not raised (well some are but so little its hard to see without thorough analysis), painfull or anything, they make the head (glans) of my penis very unsightly. what are these red dots?, they also spread onto the inside of the forskin (can see when pulled back), however they are not as bad as on the head.