Hi, my grandad has a patch of dry skin on the heel of his foot which has a black ring round the outline of it but it also looks like above it more skin is going white, tough and dry. Any ideas what it could be? He has Parkinson’s so doesn’t walk much so don’t think it’s because of shoes rubbing as he wears slippers a lot. We are waiting for the nurse to get in contact as one nurse said she was worried but gave no other info and I want to help put my nans mind at rest. Thank you in advance