Treatment of Dermatomyositis

Initial Treatment Approach

The European League Against Rheumatism recommends starting high-dose corticosteroids at diagnosis or during disease flare, followed by oral prednisolone 1-2 mg/kg/day, combined with methotrexate 15-20 mg/m² weekly, preferably administered subcutaneously, for patients with dermatomyositis 1, 2, 3
Methotrexate should be administered preferably subcutaneously for better absorption in patients with dermatomyositis 2
Patients with dermatomyositis should be provided with sun protection and ensured adequate calcium and vitamin D intake to prevent complications 1
A safe and appropriate exercise program monitored by a physiotherapist should be included in the treatment plan for patients with dermatomyositis 2

The American College of Rheumatology recommends beginning with high-dose corticosteroids and methotrexate as described above for patients with mild to moderate dermatomyositis 1, 3
Regular assessment of muscle strength, skin disease, and major organ involvement is necessary for patients with dermatomyositis 1
If improvement occurs, corticosteroids should be gradually weaned while continuing methotrexate in patients with dermatomyositis 1
If no improvement within 12 weeks, adherence and medication tolerance should be checked in patients with dermatomyositis 1, 2

Cyclophosphamide 500-1000 mg/m² IV monthly may be considered for patients with severe dermatomyositis, including those with major organ involvement or extensive ulcerative skin disease 3, 4
Alternative intensification options include high-dose methotrexate, cyclosporine A, and IVIG for patients with severe dermatomyositis 3

For methotrexate intolerance, switching to another DMARD such as mycophenolate mofetil or cyclosporin A may be considered in patients with refractory dermatomyositis 2, 3
IVIG has shown efficacy particularly for skin manifestations in patients with refractory dermatomyositis 2
Biologics such as rituximab may be effective for refractory cases of dermatomyositis, but may take up to 26 weeks to work 2
Anti-TNF therapies such as infliximab or adalimumab may be considered for patients with refractory dermatomyositis, with infliximab or adalimumab preferred over etanercept 2

Persistent skin disease reflects ongoing systemic inflammation and requires increased systemic immunosuppression in patients with dermatomyositis 2
Topical tacrolimus or topical steroids may help with localized skin disease, particularly for symptomatic redness or itching in patients with dermatomyositis 2
Intensification of immunosuppressive therapy should be considered for patients with calcinosis (calcium deposits in the skin) 2

Corticosteroid dose should be weaned as the patient shows clinical improvement in patients with dermatomyositis 2
Treatment may be withdrawn if a patient has been off steroids and in remission on methotrexate (or alternative DMARD) for a minimum of 1 year 1, 2
Regular monitoring should include assessment of muscle strength using validated measures such as Childhood Myositis Assessment Scale (CMAS) and Manual Muscle Test (MMT) in patients with dermatomyositis 2
Cutaneous disease activity should be monitored using a cutaneous assessment tool (CAT) including nailfold capillaroscopy in patients with dermatomyositis 2