What is the treatment for dermatomyositis?

Treatment of Dermatomyositis

High-dose corticosteroids combined with methotrexate should be initiated as first-line therapy for dermatomyositis, with additional immunosuppressive agents added for refractory cases. 1

Initial Treatment Approach

First-Line Therapy

• Corticosteroids:

  • Start with high-dose corticosteroids: oral prednisone 1-2 mg/kg/day or IV methylprednisolone pulses (15-30 mg/kg/dose for 3 consecutive days) 2, 1
  • Begin tapering after clinical improvement is observed
  • Prednisone is FDA-approved for systemic dermatomyositis 3

• Steroid-Sparing Agent (start concurrently with corticosteroids):

  • Methotrexate 15-20 mg/m²/week (maximum 40 mg/week), preferably subcutaneously 1
  • Acts as an effective corticosteroid-sparing agent for both muscle and cutaneous manifestations 4

Management of Refractory Disease

Second-Line Therapies

For patients with inadequate response to initial therapy:

• Intravenous Immunoglobulin (IVIG):

  • Dosage: 1-2 g/kg divided over 1-2 days, repeated monthly 1
  • Particularly effective for treatment-resistant cases 5
  • Shown to significantly improve muscle strength and neuromuscular symptoms in controlled trials 5

• Alternative Immunosuppressants:

  • Mycophenolate mofetil (MMF) 2, 1
  • Cyclosporine A 2, 1
  • Azathioprine 6

Third-Line Therapies

For severe or refractory disease:

• Biologics:

  • Rituximab (anti-CD20) 1
  • Anti-TNF therapies (infliximab or adalimumab) 1

• Cyclophosphamide: Reserved for severe, life-threatening disease 1

Specific Management Considerations

Cutaneous Disease

• Hydroxychloroquine 5 mg/kg/day for predominant skin manifestations 1
• Topical therapies:
  • Topical corticosteroids for localized lesions
  • Topical tacrolimus 0.1% 1
• Sun protection: Sunblock, wide-brimmed hats, long-sleeved shirts, UV avoidance 1

Juvenile Dermatomyositis

• Similar approach to adult dermatomyositis with some modifications
• More aggressive initial therapy may be needed to prevent complications like calcinosis 2
• Multidisciplinary approach including physiotherapists and specialist nurses 1

Monitoring and Follow-up

• Regular assessment of:

  • Muscle strength
  • Skin disease activity
  • Muscle enzymes (CK, LDH, aldolase)
  • Inflammatory markers 1

• Cardiac evaluation due to risk of myocarditis:

  • Cardiac troponin
  • Electrocardiography 1

• Malignancy screening in adult patients (3-8 times higher risk than general population) 1

Treatment Duration and Discontinuation

• Consider withdrawing immunosuppressive therapy if:
  • Patient has been in remission for at least 1 year
  • Off corticosteroids for at least 1 year 1

Pitfalls and Caveats

• Early and aggressive therapy is crucial to prevent irreversible organ damage and complications like calcinosis 2
• Ongoing skin disease may reflect ongoing systemic disease and should prompt increased immunosuppression 1
• Most significant improvement in strength typically occurs during the first 6-12 months of treatment 6
• Infections are a significant cause of mortality (5%) in treated dermatomyositis patients 6
• Treatment response may vary based on myositis-specific antibody profile, though this requires further validation 2, 7

The treatment of dermatomyositis requires a comprehensive approach with early intervention and careful monitoring to achieve optimal outcomes and reduce long-term disability.