polymyositis
Noun
Meaning
myositis characterized by weakness of limb and neck muscles and much muscle pain and swelling; progression and severity vary among individuals
Source: WordNetSynonyms
Hypernyms
Examples
A course of prednisone is typically completed with no improvement and eventually sIBM is confirmed. sIBM weakness comes on over months or years and progresses steadily, whereas polymyositis has an onset of weeks or months.
It may have different root causes unrelated to either polymyositis or sIBM.
IBM is often confused with (misdiagnosed as) polymyositis.