Juvenile Dermatomyositis Guidelines

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