lip licking rash help

[mumof2monsters]

My DS is nearly 8 and has a huge red rash around his mouth that makes him look like a clown. I guess it is from licking his lips but it looks sore and really does look awful.
He is being teased about it at school. HAs anyone else experienced this and what treatment could I use?
I have been using vaseline but not sure it is doing any good.

DD (6) does this.
I use vaseline as often as I remember (I keep it by the front door!) and gave her a Lipsil thingie for her school bag so she can put it on when she remembers/it feels sore. Not sure if it is working but she doesn't complain about it as much.

If you are worried a trip to the chemist might be worth it.