Chronic mastoiditis

This code represents a persistent, long-standing inflammation or infection of the mastoid air cells, typically a complication of chronic otitis media. It involves the bony structure behind the ear, often leading to destruction of the mastoid bone and potential spread of infection.

Apply this code when documentation clearly indicates a chronic inflammatory process affecting the mastoid, often with evidence of bone erosion or persistent drainage. This diagnosis is typically supported by imaging studies (e.g., CT scan) and clinical findings such as recurrent otorrhea, postauricular tenderness, or hearing loss.

• Differentiate from acute mastoiditis, which has a distinct code.
• Ensure documentation specifies "chronic" to support this code.
• Consider sequencing with codes for underlying conditions like chronic otitis media if applicable.