Individuals with dermatomyositis have an increased risk of developing a cancer. The malignancy may be present along with the initial symptoms or may not develop until later. The steroids used to suppress the disease and improve the weakness can cause muscle weakness if given in too high a dose, so the steroid dose requires careful adjustment.
For those individuals who respond to therapy, expected outcome is decreased severity or disappearance of symptoms (remission). The disease is disabling for individuals who do not respond.
Similar disorders causing muscle weakness are scleroderma, lupus, and rheumatoid arthritis. Other disease possibilities are hyper and hypothyroidism, chronic inflammatory polyneuropathy, multiple sclerosis, myasthenia gravis, Eaton-Lambert disease, and amyotrophic lateral sclerosis. Many drugs and alcohol can also produce muscle weakness. The rash of dermatomyositis can be similar to lupus, psoriasis, lichen planus, and mycosis fungoides.
Rheumatologist, oncologist (if cancer is present), neurologist, physiatrist, and dermatologist.
Last updated 6 July 2015