My dad,& 2 of my uncles (brothers) all have sores on their arms, & we cant figure out what they are! My dad 1st started getting them..they start out as blisters that itch , in return he scratches them & then they turn into sores, that are permanantly there. 2 of them have been to 2 different dermatologists, to only be told, that they are self inflicted . WHAT COULD THEY BE?! I honestly think it s something hereditary, but WHAT? Thanks!