You say that your son explores a lot. Does he retract his foreskin? Is the swollen foreskin retracted behind the head? If the foreskin is retracted behind the head and swollen, then it likely is edematous and your son has paraphimosis. Paraphimosis is a medical emergency if you can't return his foreskin to the normal forward position. You should take him to the emergency room.
6/4/13 at 7:46pm