The hallmark of<unk>  is weakness and/or loss of muscle mass in the proximal musculature, as well as flexion of the neck and torso. These symptoms can be associated with marked pain in these areas as well. The hip extensors are often severely affected, leading to particular difficulty in climbing stairs and rising from a seated position. The skin involvement of dermatomyositis is absent in<unk> . Dysphagia (difficulty swallowing) or other problems with esophageal motility occur in as many as 1/3 of patients. Low grade fever and enlarged lymph nodes may be present. Foot drop in one or both feet can be a symptom of advanced<unk>  and inclusion body myositis. The systemic involvement of<unk>  includes interstitial lung disease (ILD) and heart disease, such as heart failure and conduction abnormalities.<unk>  tends to become evident in adulthood, presenting with bilateral proximal muscle weakness often noted in the upper legs due to early fatigue while walking. Sometimes the weakness presents itself as an inability to rise from a seated position without help or an inability to raise one's arms above one's head. The weakness is generally progressive, accompanied by lymphocytic inflammation (mainly cytotoxic T cells). Associated illnesses<unk>  and the associated inflammatory myopathies have an associated increased risk of cancer. The features they found associated with an increased risk of cancer were older age, age greater than 45, male sex, difficulty swallowing, death of skin cells, cutaneous vasculitis, rapid onset of myositis (<4 weeks), elevated creatine kinase, higher erythrocyte sedimentation rate and higher C-reactive protein levels. Several factors were associated with lower-than-average risk, including the presence of interstitial lung disease, joint inflammation/joint pain, Raynaud's syndrome, or anti-Jo-1 antibody. The malignancies that are associated are nasopharyngeal cancer, lung cancer, non-Hodgkin's lymphoma and bladder cancer, amongst others. Cardiac involvement manifests itself typically as heart failure, and is present in up to 77% of patients. Interstitial lung disease is found in up to 65% of patients with<unk> , as defined by HRCT or restrictive ventilatory defects compatible with interstitial lung disease.
Polymyositis
Scleroderma
Dermatopolymyositis
Dermatomyositis
Inclusion body myositis
Nemaline myopathy
Inflammatory myopathy
Metabolic myopathy