4 yr old pulling at penis

I have a 4 yr old that has been pulling at his penis.  This is not masterbation (masturbation), but something different.  He has been circumcised since shortly after birth.  He says that his penis is sticking to his underwear, but this does not seem right either.  I see nothing in his underwear.  His penis looks fine.  We have changed underwear but the problem is only getting worse.  He is not pulling at his penis about every 5-10 seconds.  What can be the problem?

[felinaboricua21]

It's probably getting bigger. My son used to do the same thing (also scratch a lot). I asked my mother to know if my brother used to do the same at that age and she said yes. Is just the same way as when our breast is growing, remember that sensation? Just exclude the pain. I used to give my son lotion so he could rub it on and this usually made things better. When outside is the real problem because he will still feel uncomfortable and start grabbing himself in plain view. Try to always have a small bottle of lotion for when outside and when no one is looking or behind a car let him apply it. Hope this was helpful. Don't worry this wont last forever. My son is 5 and he stopped a few months before his birthday.