Prognosis

Classic dermatomyositis

With treatment, prognosis has improved with 5-year survival of 95% and 10-year survival of 84%.[187] However, despite improved survival rates, one third of patients will experience permanent disability that can be severe.[188][189]

Although some patients have an acute illness and do not require long-term maintenance therapy, most experience a chronic disease with a relapsing-remitting course. Most patients require long-term treatment with corticosteroids or other immunosuppressant agents and many experience complications related to this.

Amyopathic dermatomyositis

Patients with clinically amyopathic DM may have subclinical evidence of muscle disease (hypo-myopathic) or may be truly amyopathic, and often present early with cutaneous manifestations.

Response to treatment of subclinical muscle disease may be better as a result of early diagnosis and treatment or less severe myositis.[96] Cutaneous disease is often more resistant to treatment and can cause significant morbidity.[96]

Amyopathic patients require continued follow-up to screen for the development of muscle disease. In the absence of malignancy the prognosis is good.[190][191]

Prognostic indicators

Several factors are associated with a poorer outcome. These include:

  • Delay in treatment for >6 months after symptom onset[129][192]

  • Greater muscle weakness at presentation[193]

  • Respiratory muscle involvement[194]

  • Interstitial lung disease[188]

  • Malignancy[188]

  • Dysphagia[193]

  • Cardiac involvement.[194]

Use of this content is subject to our disclaimer