Symptoms of lupus-related myositis include muscle pain, joint pain, fatigue and general feelings of illness. Persons affected by myositis may experience labored breathing and have difficulty swallowing. Weight loss may accompany lupus myositis, according to the Arthritis Foundation.
Myositis refers to inflammation of muscle tissue. Lupus myositis symptoms affect skeletal muscles of the shoulders, upper arms, neck, thighs and pelvis. More than 90 percent of lupus patients experience myositis or muscle pain known as myalgia. Lupus flare-ups increase the odds of muscle pain and weakness, according to the Lupus Foundation of America.
Myositis may overlap with autoimmune disorders such as lupus, scleroderma and rheumatoid arthritis. According to the Myositis Association, approximately 1 percent of the population is affected by rheumatoid arthritis. Lupus affects about 0.5 percent of the population.
Myositis can also be caused by infection, especially viral infections. Flu viruses, HIV and the common cold virus can trigger myositis. Bacterial and fungal infections are lesser causes of myositis, says WebMD.
As of 2015, there is no cure for lupus. Treatment to manage the symptoms of lupus and lupus-related myositis include acetaminophen and nonsteroidal anti-inflammatory drugs. Hydroxychloroquine and other antimalarial medications may be prescribed to manage lupus, according to WebMD.