In dermatomyositis, which laboratory finding is commonly elevated?

In dermatomyositis, which laboratory finding is commonly elevated?

• A. Erythrocyte sedimentation rate
• B. C-reactive protein
• C. Antinuclear antibody
• D. Creatine phosphokinase

Answer: (D)

In inflammatory myopathies like dermatomyositis, muscle fiber damage spills skeletal muscle enzymes into the blood. Creatine kinase is a muscle-specific enzyme, and its elevation directly reflects the extent of muscle injury and typically tracks disease activity. While ESR and CRP are nonspecific inflammatory markers and ANA can be positive in many autoimmune conditions, they don’t specifically indicate muscle injury. Thus, creatine kinase is the most characteristic and commonly elevated lab finding in dermatomyositis.

In inflammatory myopathies like dermatomyositis, muscle fiber damage spills skeletal muscle enzymes into the blood. Creatine kinase is a muscle-specific enzyme, and its elevation directly reflects the extent of muscle injury and typically tracks disease activity. While ESR and CRP are nonspecific inflammatory markers and ANA can be positive in many autoimmune conditions, they don’t specifically indicate muscle injury. Thus, creatine kinase is the most characteristic and commonly elevated lab finding in dermatomyositis.