Dermatomyositis (DM) is classified both as a neuromuscular disease and an autoimmune disease. It is thought that the inflammation resulting in cell damage is created when the immune system attacks healthy muscle tissue and blood vessels under the skin. -- From Myositis Support and UnderstandingBasically, DM is so rare researchers are still learning about this disease (as well as all the myositis'), and they go back and forth as to whether it is an autoimmune and/or neuromuscular disease (hence my "worst of both worlds), which is why myositis is considered to also be under the Muscular Dystrophy "umbrella". The only way to keep research continuing is to help raise awareness, and it is as easy as sharing as much as you can about these diseases! Raising awareness is saving lives. It was not too long ago (literally within the last 10 years) that the prognosis for DM was about 5 years. Now people are living many, many years thanks to the increase in awareness which has resulted in an increase in research. Please help keep that going!