<unk>  is a family of myositis disorders that includes polymyositis and dermatomyositis. As such, it includes both a distinctive skin rash and progressive muscular weakness. It is a rare disease.
Dermatopolymyositis
Polymyositis
Inclusion body myositis
Nemaline myopathy
Dermatomyositis
Inflammatory myopathy
Centronuclear myopathy
Polymyalgia rheumatica