What is inflammatory myopathy?
Inflammatory myopathy is a rare disease involving chronic inflammation and weakness of muscles with no known cause. Sometimes a rash may also develop due to this condition. It is categorized as an autoimmune disorder and there are several different inflammatory myopathy diseases present that require different treatments.
Who develops inflammatory myopathy?
This condition can affect both adults and children, so all ages are capable of developing these diseases. In certain myopathies, women are twice as likely to develop myopathy than men. All ethnic groups can develop an inflammatory myopathy.
Where does inflammatory myopathy occur?
The main areas that inflammatory myopathy affects are the large muscles of the neck, shoulders, and hips.
What are the different types of inflammatory myopathies?
Currently, there are four chronic inflammatory myopathy conditions present. They include:
- Polymyositis affects the skeletal muscles, therefore, impacting the movement of those diagnosed with this particular myopathy. It affects both sides of the body and is more common in women. The onset of this condition ranges from around 30-60 years of age. The prognosis for this condition varies, but most respond well with treatment therapies. If therapy is not successful, some individuals may develop severe disabilities due to this condition.
- Dermatomyositis- includes a skin rash and progressive muscle weakness. The rash may present as purple or red spots on the upper eyelids or as scaly, red bumps over the knuckles, elbows, or knees. Women and children tend to develop this condition more. Children can develop calcium deposits underneath the skin from this condition and inflammation of the blood vessels. Lung inflammation is also common in this form, causing coughing or shortness of breath. Prognosis is good with this type of inflammatory myopathy with treatment. One-third of juvenile cases will recover.
- Inclusion body myositis- involves progressive muscle weakness and shrinkage. People over the age of 50 and men are more susceptible to developing this type of myopathy. This type of myopathy has the poorest prognosis as it is resistant to all treatment modalities at this time.
- Necrotizing autoimmune myopathy- symptoms of this particular myopathy are weakness in the upper and lower body, fatigue, and muscle pain. This myopathy responds the best with long-term combination immunosuppressive therapy.