Dermatomyositis (DM) is rare, idiopathic, and one of four forms of inflammatory myopathy. It is marked by muscle weakness and rash. People with DM often experience pain, difficulty climbing stairs, difficulty swallowing, arthritis, and many have a variety of skin changes.
Yearly incidence of DM is between 1 to 10 people per million, and the prevalence is between 1/50,000 and 1/10,000.
The specific underlying cause of DM remains unknown. However, evidence suggests that genetic, immune, and environmental factors could play a role, including viral infections, sun exposure, smoking and certain medications.
Next tabCan appear suddenly or develop gradually over time and include:
- Distinctive, patchy, dark reddish/purple heliotrope rash on the cheeks and bridge of nose
- Heliotrope, itchy or painful rash or scaling on the eyelids, face, forehead, scalp and elbows
- Calcinosis (calcium deposits)
- Muscle weakness in the hips, thighs, shoulders, upper arms and neck
- Panniculitis (painful lumps)
Previous tabNext tabGender
DM is twice as common in women than in men.
Race or Ethnicity
It is three times as common in Blacks than in Whites.
Age
It is most common in people who are 40 to 60 years of age.
Previous tabNext tabThere are limited effective therapies for DM. Current treatment options include high-dose corticosteroids and other immunosuppressive agents to help manage DM, but these can have serious side effects. Physical therapy and exercise may play a beneficial role in managing DM.
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