Cut marks on penis skin at the end.

Sometimes 2-3 hairline sized cut marks develop on the outer skin of my penis at the tip. It generally takes 2-3 days for them to heal. If I masturbate during the healing process the cut takes more time to heal as the cut becomes fresh on expansion while pulling back as it is at the tip of foreskin. I generally apply lotion or cream on it to heal early. But I am not aware of the reason why it develops. I generally wash and clean penis after urination as a part of habit for hygiene. Still it happens...What is the reason for the problem and why it happens. It is not even permanent it only appears sometimes.what is the permanent cure for it if circumcision is to be avoided. What precautions should be taken to avoid the problem.