What can I put on baby DD's sore thumb .. she's a thumb-sucker

[TheHollyAndTheTwiglett]

And in the crease between her thumb and forefinger she has a red patch which could be excema or could equally be cos she sucks it and it rubs against her lip / sole tooth

I would normally put sudacrem on it but as its the thumb she sucks any suggestions please?

my dd1 developed one of these and I think it was where the saliva drips down and collects in the crease, so it is permanently wet and goes a bit soft and manky. I put vaseline on it when I could to protect it against the wet, eventually it developed a kind of callus