Epidermolysis bullosa (EB) "is a group of blistering skin conditions. The skin is so fragile in people with EB that even minor rubbing may cause blistering. ... In severe EB, blisters are not confined to the outer skin. They may develop inside the body." Includes information about causes, diagnosis, symptoms, treatment, and genetic testing for EB, and links to related sites. From the National Institutes of Health (NIH).