Dermatomyositis

By:Elizabeth Williams

Orphan Disease

An orphan disease is any disease that affects a small percentage of the population.


Synonyms

  • ADM
  • Childhood dermatomyositis
  • Idiopathic inflammatory myopathy
  • IIM
  • Polymyositis

General Description

Dermatomyositis is a progressive connective tissue disorder characterized by inflammatory and degenerative changes of the muscles and skin. Skin abnormalities associated with dermatomyositis often include a distinctive reddish-purple rash (heliotrope rash) on the upper eyelids, across the cheeks and bridge of the nose in a "butterfly" distribution, the forehead, or additional skin regions; scaling and degenerative (atrophic) changes of affected skin on the extending surfaces of the knuckles, elbows, knees, and/or other regions (Gottron's sign); an abnormal accumulation of fluid (edema) in body tissues surrounding the eyes; and/or other features.

Signs & Symptoms

  • muscle weakness
  • muscles may be stiff, sore, and/or tender
  • degeneration and muscle wasting
  • awkward manner of walking
  • gradual inability to perform certain tasks: such as lifting the arms, climbing steps, or dressing
  • inability to raise the head from the pillow when lying down
  • difficulties swallowing (dysphagia)
  • distinctive reddish-purple or lilac (i.e., heliotrope) rash

Causes

The specific underlying cause or causes of dermatomyositis remain unknown. However, evidence suggests that genetic, immune, and environmental factors play some role.

Affected Populations

  • Infancy through approximately age 80
  • More commonly between 40 to 60 years
  • Symptoms usually appear between the ages of five to 15 years
  • Approximately three in 1,000,000 children are affected by juvenile dermatomyositis
  • Females are affected by Dermatomyositis twice as often as males.

Related Disorders

  • Polymyositis
  • Inclusion Body Myositis
  • Scleroderma
  • Systemic lupus erythematosus (SLE)

Diagnosis

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

Standard Therapies

  • The treatment of dermatomyositis is directed toward the specific symptoms that are apparent in each individual
  • Affected children may initially require high dose therapy with prednisone, which often results in a return of muscle enzyme levels toward normal levels within about one to two weeks
  • As with adults, decreased muscle inflammation and improved muscle strength typically follow.
  • Therapy with other immunosuppressive drugs, such as azathioprine, methotrexate, cyclophosphamide, chlorambucil, or cyclosporine, may be beneficial for some affected individuals who have an insufficient response to corticosteroid therapy alone, dose-limiting adverse effects, or frequent relapses.

Supporting Organizations

  • American Autoimmune &Related Diseases
  • Myositis Association
  • Arthritis Foundation
  • Muscular Dystrophy Association