Thanks a lot all of you! It's good to know that we are not alone.
What we tried so far:
going to the vet - he prescribed antihistamine - did not work
another visit to the vet - change the diet to rice and lamb - did not work
home remedy - washing the paws everyday with Physoderm - works
home remedy - telling her to stop - works ...sometimes
home remedy - treating her paws with hydrogen peroxide - worked for a while
home remedy - put her shoes on - works of course, but I don't like her to wear them all the time
any other suggestions?
Thanks again!