Polymyositis is a rare autoimmune and sometimes paraneoplastic inflammatory myositis.
The term “polymyositis” is applied when the condition spares the skin, and “dermatomyositis,” when polymyositis is associated with a characteristic skin rash.
Polymyositis typically has a symmetric distribution, initially involving the proximal lower limb girdle and progressing to involve the proximal upper limb girdle, neck flexors, and pharyngeal muscles1.