In the last 6 weeks or so I've slowly developed a rash on my forearms. It began, one tiny blister at a time, on my left arm. The blister is small, doesn't itch and easily breaks. It's gradually spread down my left arm and is now on my right arm. The blister spots become red and take forever to heal. And again, it doesn't itch. It's really unsightly and just keep spreading. Any ideas?