Infective myositis, multiple sites

This code signifies inflammation of muscle tissue caused by an infectious agent affecting multiple, non-contiguous anatomical locations. It represents a systemic or widespread muscular infection rather than a localized one.

Apply this code when documentation clearly indicates myositis due to an infection (bacterial, viral, fungal, parasitic) impacting more than one distinct muscle group or body region. Supporting documentation should specify the infectious etiology and the multifocal nature of the muscle involvement.

• Ensure the documentation explicitly states "multiple sites" or lists several affected muscle groups to differentiate from localized infective myositis.
• Always code the underlying infectious agent first, if known and documented, followed by this code.
• Do not use this code for non-infectious myositis (e.g., autoimmune) or for a single, localized infective myositis.