i agree that blood vessels are probably damaged because they are connected to the stratum corneum. If you take a knife and make a very tiny slit on normal persons lips there will be guarantied blood....the other thing i still cant figure out is why the lips only peel in those certain areas. for most people the majority of the upper lip and the lower part of the lower lip seems to be fine...
so could it be that the lips try to produce skin cells but there are no blood vessels to keep them alive, SO THEY DIE?
and could it also be that the reason for the build up is not really estrogen...the lips are producing skin cells because they are trying to heal, but then they die and just pile up and this continues?
mayebe
lips produce skin then they die, then it produces again then they die <----this will lead to a thick pile of dead skin which is exactly what we have.