Adorable animal families that will make you aww. A skin disease is a disease which involves the skin. Specialists in these diseases are known as dermatologists, and diseases of the skin are quite diverse, making plenty of work available in the field of dermatology.ake the bullous skin disease, for example. I think that this is one of the saddest diseases that anybody can get, because it's a genetic autoimmune disorder. In bullous skin disease, large blisters form on the body as the skin which periodically erupt, and may become infected.