Dermatomyositis

What is dermatomyositis?

Dermatomyositis is a rare inflammatory disease marked by muscle weakness and a distinctive skin rash. Dermatomyositis is distinguished from juvenile dermatomyositis. Although these two conditions share the same hallmark features, they are separate diseases with a range of additional disease features and complications.

What are the symptoms of dermatomyositis?

Body/skin symptoms of dermatomyositis include:

Skin rashes on photo-exposed surfaces
Pruritus of skin lesions, sometimes severe enough to disturb sleep
Erythema of the mid-face
Rashes along the eyelid margins
Rashes on the dorsal hands, particularly over the knuckles
Changes in the nailfolds of the fingers
Rashes on upper outer thighs
Scaly scalp or hair loss

Muscle symptoms of dermatomyositis include:

Proximal muscle weakness
Muscle fatigue while active (walking, climbing, rising from a seated position, or reaching for items above shoulders)
Muscle tenderness

What causes dermatomyositis?

The exact cause of dermatomyositis is unknown, but the disease shares many characteristics with autoimmune disorders, in which the immune system attacks the body.

How is dermatomyositis diagnosed?

Dermatomyositis may be diagnosed based upon a detailed patient history, thorough clinical examination, detection of characteristic physical findings, and certain specialized tests. These tests include:

EMG
MRI
Muscle biopsies
(CT) scanning
Chest radiography
Barium swallow
Ultrasound of the muscles affected

What treatments are available for dermatomyositis?

The following medications are used in the management of dermatomyositis:

Corticosteroids (e.g. prednisone)
Immunosuppressive agents (e.g. methotrexate, mycophenolate mofetil, azathioprine, rituximab, sirolimus)
Immune globulins (e.g. intravenous or subcutaneous immunoglobulin)
Antimalarial agents (e.g. hydroxychloroquine, chloroquine)
Diltiazem
Colchicine
Alendronate
Warfarin