Diagnostic Evaluation for Myositis and Their Pitfalls.

Myositis is a systemic autoimmune disorder that affects multiple organ systems, including the skeletal muscles, lungs, skin, and joints. The clinical presentation can vary significantly, and physicians must tailor the diagnostic evaluation for each patient, reflecting a personalized approach rather than relying on a standardized routine order set. Each diagnostic test has its own advantages, limitations, and pitfalls, requiring careful interpretation of results to make appropriate clinical decisions. In this article, we discuss the clinical applications of laboratory tests, myositis antibodies, imaging, electromyography, and muscle histopathology with key points to consider when interpreting the results.