| Dermatomyositis (PM/DM) |
| Onset: |
Childhood to late adulthood. |
| Symptoms: |
Weakness of neck and limb muscles. Muscle pain and swelling common. Skin
rash typically affecting cheeks, eyelids, neck, chest and limbs. |
| Progression: |
Disease progression and severity vary among individuals. Often responds
to drug therapy. |
| Polymyositis (PM/DM) |
| Onset: |
Childhood to late adulthood. |
| Symptoms: |
Weakness of neck and limb muscles. Muscle pain and swelling common. Sometimes
associated with malignancy. |
| Progression: |
Disease severity and progression vary among individuals. Often responds
to drug therapy. |
| Inclusion Body Myositis (IBM) |
| Onset: |
After age 50. |
| Symptoms: |
Weakness of arms, legs and hands, especially thighs, wrists and fingers.
Sometimes involves swallowing muscles. |
| Progression: |
Slowly progressive. More common in men than women. |
