Dermatomyositis & myositis
Inflammatory myopathies
Autoimmune conditionAutoimmune conditions in which the immune system inflames the muscles, causing weakness. Dermatomyositis also causes a distinctive rash.
What happens
The immune system attacks muscle tissue (and, in dermatomyositis, small blood vessels in the skin and muscle). Weakness usually affects the muscles closest to the trunk: hips, thighs, shoulders, and neck. Some forms also affect the lungs or swallowing. In adults, dermatomyositis is sometimes linked to an underlying cancer, so screening is part of care.
Who gets it
Dermatomyositis is about twice as common in women and most often starts between 40 and 60. There's also a childhood form.
Common signs
- Trouble climbing stairs, rising from a chair, or lifting your arms overhead
- Muscle aches or tenderness
- A purple-red rash on the eyelids
- Red, scaly bumps over the knuckles
- A rash on the chest, back, or shoulders that worsens in the sun
- Trouble swallowing
- Shortness of breath or a dry cough
Labs to ask about
- CK (creatine kinase) and aldolase
- Myositis-specific antibodies and ANA
- EMG, muscle MRI, or muscle biopsy
- Lung function tests and chest imaging
- Age-appropriate cancer screening
How it's usually treated
- Steroids together with steroid-sparing immune medicines
- IVIG for some people
- Physical therapy
- Sun protection for skin disease
Supportive steps to discuss with your provider
- Once inflammation is controlled, rebuild strength with guided exercise.
- Protect your bones while taking steroids. Ask about vitamin D and calcium.
- Use strict daily sun protection.
See a doctor promptly if you have
- Trouble swallowing or choking on food or drinks
- Shortness of breath
- Weakness that's getting worse quickly
Related conditions
Lupus
A whole-body autoimmune disease that can inflame the skin, joints, kidneys, blood, heart, lungs, and brain.
Learn more →Scleroderma
The immune system drives thickening and scarring of the skin, and sometimes internal organs, along with damage to small blood vessels.
Learn more →Mixed connective tissue disease
An overlap condition with features of lupus, scleroderma, and myositis, marked by high levels of an antibody called anti-U1 RNP.
Learn more →
Wondering if your symptoms fit a pattern?
Dr. Lesher is a naturopathic doctor who specializes in women's autoimmune and chronic conditions. Since 2020, she has helped more than 900 patients overcome and heal from their conditions.