What is the next best step for a patient with decreasing muscle strength, currently on methotrexate (MTX) and oral steroids, who previously responded to IV steroid pulse therapy?

Management of Worsening Muscle Strength in Dermatomyositis

For a patient with decreasing muscle strength (from 27/52 to 24/52) who is currently on methotrexate and oral steroids with previous IV steroid pulse therapy, the next best step is to intensify treatment by adding intravenous immunoglobulin (IVIG) therapy.

Assessment of Current Situation

The patient presents with:

• Deteriorating muscle strength (decreased from 27/52 to 24/52 over 2 weeks)
• Current treatment includes:
  • Methotrexate (MTX)
  • Oral corticosteroids
  • Previous IV steroid pulse therapy

This pattern indicates a refractory or inadequately controlled case of dermatomyositis with progressive muscle weakness despite conventional therapy.

Treatment Algorithm for Worsening Dermatomyositis

Step 1: Evaluate Current Treatment Adequacy

• Decreasing muscle strength scores indicate inadequate response to current therapy
• The combination of MTX and oral steroids is appropriate first-line therapy, but clearly insufficient in this case

Step 2: Intensify Treatment

According to the SHARE consensus guidelines for juvenile dermatomyositis management, when patients show inadequate response to MTX and corticosteroids, treatment intensification is required 1:

• For patients with inadequate improvement on current therapy, intensification is recommended by:
  • Adding IVIG
  • Changing to anti-TNF therapy (infliximab or adalimumab)
  • Using combination therapy with high-dose MTX, cyclosporine A, and IVIG

Step 3: Specific Recommendation

The most appropriate next step is to add IVIG therapy while continuing the current medications:

• IVIG dosing: 1-2 g/kg divided over 1-2 days, repeated monthly 2
• Continue current MTX and oral corticosteroids

Evidence Supporting This Approach

The SHARE consensus guidelines provide a clear treatment algorithm for refractory dermatomyositis, recommending intensification of treatment when patients show inadequate response 1. A retrospective analysis demonstrated that adding IVIG (2 g/kg) to immunosuppressants in patients with refractory myositis resulted in significant improvement in muscle strength and function 3.

Important Considerations

1. Monitoring: Continue regular assessment of:

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

2. Alternative Options if IVIG fails:

   • Rituximab
   • Anti-TNF therapy (infliximab or adalimumab)
   • Mycophenolate mofetil
   • Cyclosporine A

3. Caution: Avoid rapid tapering of corticosteroids during this disease flare, as this could further worsen symptoms.

4. Multidisciplinary Care: Ensure involvement of rheumatology, physical therapy, and potentially dermatology for comprehensive management.

The deteriorating muscle strength despite current therapy necessitates prompt treatment escalation to prevent further decline in function and potential complications such as respiratory muscle weakness or dysphagia.