Dermatomyositis is a rare autoimmune condition, whereby one’s own immune system develops a response against one’s own cell, usually in the skin and muscles and sometimes other organs (e.g. joints, lungs, and gut).
Who gets dermatomyositis ?
Both children and adults can get dermatomyositis. In adults, when someone is diagnosed with dermatomyositis, an internal cancer screening is done because a portion of people who develop this as adults may have underlying internal malignancy, such as ovarian cancer.
How do I know if I have it ?
Dermatomyositis involving the skin is best diagnosed by a dermatologist. It often displays a pink scaly rash on the knuckles and sometimes the elbows (Gottron papules), eyelids (this is usually purple, referred to as heliotrope), neck region (“shawl sign”), lateral thighs (“holster sign”), scalp (often mistaken for other types of inflammation of the scalp) and other areas. This rash is often very itchy. There may also be nail fold changes. While the rash can be very characteristic clinically, usually a biopsy is done to confirm the diagnosis. Additionally, the rash may be accompanied by some proximal muscle weakness (felt in arms when brushing hair or in thighs when going up stairs).
How can I treat it ?
Dermatomyositis often needs the attention of a dermatologist and a rheumatologist. In adults, age-appropriate cancer screening is usually done, and possibly some imaging studies. The rheumatologist will manage the muscle and other systemic symptoms if present (other specialists may be needed, depending on the organ involved). This may require the use of oral and other systemic immunosuppressants. Skin targeted therapies often involve sun protection, topical steroids and other topical immunosuppressants, steroid injections into the scalp (in cases of scalp involvement), anti-itch topical and oral therapies (e.g. antihistamines), as well as oral antimalarial medicines (e.g. hydroxychloroquine -Plaquenil). When dystrophic calcinosis is present, additional therapeutic options may also be needed.
When should I see a dermatologist about it ?
You should see a dermatologist for this as soon as the rash presents itself to diagnose and treat it promptly, as well as to advise on any necessary screening. Your dermatologist will likely co-manage it with a rheumatologist.
Additional Resources:
The Myositis Association