What Causes Itchy Blisters On Skin?

My husband works with a man who drinks a couple of six packs of beer a day. He currently has a skin disorder has visited six different physicians who don't have a clue as to what is wrong. I am sure he did not tell any of them the quantity of beer he drinks. I saw his skin and it looks like he has tiny blisters. They itch Started out on his his face and now is traveling down his trunk and arms. He has rubbed away skin on his face. Why the difficulty in diagnosis? Any idea what could cause this?