9th June 2025

Diagnosis

The diagnosis of dermatomyositis is complex with many criteria such as the “Bohan and Peter criteria” being proposed. In general, the following features are present:

• Symmetrical muscle weakness
• Elevation of muscle enzymes: High creatinine kinase levels is a sensitive but not a specific marker
• Presence of autoantibodies: in particular, Myositis Specific Antibodies being present in approximately 50% of all diagnoses
• Muscle biopsy evidence: Perivascular inflammation
• Cutaneous involvement
• Electromyographic/Magnetic resonance imaging evidence of disease activity