Juvenile Dermatomyositis Guidelines

Updated: May 12, 2021
  • Author: Ann M Reed, MD; Chief Editor: Lawrence K Jung, MD  more...
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Guidelines

Guidelines Summary

Guidelines on the management of juvenile dermatomyositis were made by an expert panel using the European League Against Rheumatism standard operating procedures. The guidelines included the following recommendations  [106] :

In every patient with a possible diagnosis of JDM, the following should be considered:

  • Muscle enzymes—including creatinine phosphokinase (CPK), LDH, AST (SGOT), ALT (SGPT), adolase (if available)

  • Full blood count and blood film

  • ESR (or plasma viscosity) and CRP

  • Myositis-specific and myositis-associated antibodies

  • Renal function and liver function tests

  • Infection screen (for differential diagnosis)

  • Investigations for alternative systemic causes of myopathy, including endocrine disorders (especially thyroid function), electrolyte disturbances, and vitamin D deficiency

  • Further tests for metabolic/mitochondrial myopathies (especially in the absence of rash/atypical presentation)

  • Urine dipstick (with further evaluation if positive for protein)

  • Nailfold capillaroscopy

  • Echocardiogram and ECG

  • Pulmonary function tests (chest x-ray and HRCT if concern)

  • MRI of muscles (+quantitative ultrasound)

  • EMG (particularly if suspicion of neuropathy/disorder of neuromuscular junction)

  • Muscle biopsy (especially in the absence of rash/atypical presentation)

  • MRI brain if neurologic involvement suspected

  • Abdominal ultrasound scan

High-risk patients are defined by the following:

  • Disability defined by inability to get off the bed

  • CMAS (Childhood Myositis Assessment Scale) score < 15 or MMT8 (Manual Muscle Test) score < 30

  • Presence of aspiration or dysphagia

  • Gastrointestinal vasculitis

  • Myocarditis
  • Parenchymal lung disease

  • CNS disease (decreased level of consciousness or seizures)

  • Skin ulceration

  • Requirements for ICU management

  • Age < 1yr

Treatment recommendations:

  • High-dose corticosteroids should be administered orally or by IV in moderate to severe JDM.

  • For new-onset JDM, high-dose corticosteroids by oral or IV route with methotrexate (MTX).

  • MTX should be started at a dose of 15–20 mg/m2/wk (max absolute dose of 40 mg /wk) preferably administered subcutaneously at disease onset.

  • Ongoing skin disease reflects ongoing systemic disease and therefore should be treated by increasing systemic immunosuppression. Topical tacrolimus (0.1%)/topical steroids may help localized skin disease, particularly for symptomatic redness or itching.

  • For patients with severe disease (such as major organ involvement/extensive ulcerative skin disease), addition of intravenous cyclophosphamide should be considered.