help with licking chin

Hi, This is a strange one, and i have searched google trying to find some help or advice. My daughter is 2 and a half, and for about 2 or 3 months now, she constantly licks her chin, her chin and around her mouth is getting all spotty and red now, but she just wont stop no matter what we say, she does it all day long and have no idea why.
Has anyone heard of this, or have any advice on what we can do to break this habbit?
Thanyou in advance.

my son Ben did this. i used to have to put vaseline on his chin it got so sore and dry. he just stopped doing it. i think you need to ignore it hun. dont say anything to her, just keep putting vaseline (or whatever you use) on her chin. thats what i did and he's stopped it. hope that helps

my DD did it too and was sore but she just stopped onher own after a while

my eldest did it too she did it for about 6 months and soon stopped when she was complaining of her chin being sore all the time.
thnk its just one of those habits they grow out of

thankyou all for your replies, looks like just something she will grow out of then . we were worried it would become a permanent habbit.