My baby boy is 7 weeks old and for the past couple of days I have noticed his top lip is very dry and there is a sort of - bubble of skin - that is dry, no fluid in it. Today when he woke up it was ripped and hanging down and obviously annoying his although I am loathed to pull it off in case that hurts him.
my babies have had this too, I think it's caused by friction when feeding. Mine were breastfed so it's not bottle feeding that caused it! I didn't pull it off, just waited until it fell off. Vaseline sounds like a good idea though