Myositis: Frequently Asked Questions

Featured in the December, 2012 Scleroderma, Vasculitis & Myositis eNewsletter.

What is myositis?

Myositis is an autoimmune condition characterized by inflammation of muscle. The symptoms include weakness and sometime even muscle pain. Myositis is the main feature of polymyositis, dermatomyositis and inclusion body myositis, however patients with scleroderma and vasculitis can also have myositis as a secondary feature.

It is important to note that there are other causes of muscle weakness and pain such as drug toxicities and viral infections, so these possibilities must be considered as well.

Are causes of myositis being investigated?

Yes. Research is being done in the area of genetics and possible environmental causes of many autoimmune diseases. For example, in lupus, looking at identical twins, where one twin has developed lupus and the other has not. This lends toward researching susceptibility and environmental factors.

View the latest Scleroderma, Vasculitis & Myositis studies and clinical trials presently underway at HSS.

What percent of people with myositis have other autoimmune disease?

About 10% of people with myositis have elements of other autoimmune disease.

How do we know if we are losing muscle strength?

This can be difficult to assess. Though not always reliable, muscle damage can be determined by creatine kinase levels (CK) and what is reported from doctor to patient.

Testing, such as EMG testing, in addition to discussion with your doctor, is probably the most reliable way to determine loss of muscle strength.

How is the diagnosis of polymyositis versus dermatomyositis made?

This can be difficult, as both types of myositis can look like other diseases. A biopsy is usually the most reliable method to diagnose. In dermatomyositis, we might also see more skin involvement- such as a rash.

Are there “patterns” in myositis?

Yes. It is estimated that 15% of people with myositis may experience one flare. A larger group experiences flares that are separated by periods of disease inactivity. The largest group; however, experiences flares, separated by periods of relatively mild disease activity.

What are some signs of a flare?

Some signs of a flare can include:

• muscle weakness (being tired, increased difficulty going up and down stairs)
• higher CK level
• fever
• patient reporting
• in dermatomyositis, there may be worsening of a rash

Is exercise important?

Yes. It is important to exercise to help prevent loss of muscle. However, each person’s situation is unique. Any exercise routine should first be discussed with one’s physician. Exercise should also be modified according to one’s condition at any time, such as when one is in a flare, and one’s physician should be consulted if this occurs.

What cholesterol medications can a person with myositis use?

This is a difficult question to answer and one that must be discussed with one’s own physician. It is unknown if there is an increase in statin (cholesterol medication) myopathy in patients with myositis or if it can help to cause a flare.

What can be done for fatigue?

First, discuss this with your own physician. Together, you may decide on a course of action that may include blood tests for CK level and anemia. It is common for inflammation to increase fatigue. It is important to try to rest as much as possible.

Are there any specific recommendations regarding diet and myositis?

There are no clear answers regarding this. While it might be said that certain foods may reduce inflammation, there has not been enough research done. In part, this is due to the fact that the pool used for studies in people with myositis is a small one- as it is a rare disease.

The best advice that can be offered at this time is that a healthy, balanced diet is recommended. Also, we know that certain medications, such as prednisone, can put you at risk for diabetes and osteoporosis. Therefore it is important to consider diet control and increased calcium when taking prednisone.

Learn more about the Scleroderma, Vasculitis & Myositis Center.

Posted: 12/20/2012