Polymyositis mimics
| Endocrine myopathies | |
| Hyperthyroidism | |
| Hypothyroidism | |
| Drug or toxic myopathies | |
| Metabolic myopathies | |
| Mitochondrial myopathies | |
| Muscular dystrophies | |
| Infectious myositis | |
| Neuropathies and neurologic syndromes | |
| Paraneoplastic syndromes | |
| Other connective tissue disorders | |
| Miscellaneous | |
| Amyloidosis | |
| Sarcoidosis |