Subperiosteal abscess of mastoid, bilateral

This code signifies an infection with pus accumulation located beneath the periosteum of the mastoid bone, affecting both ears. It represents a serious complication of otitis media, often indicating a progression of infection beyond the mastoid air cells.

Use this code when documentation explicitly states a bilateral subperiosteal abscess of the mastoid. This typically occurs in patients presenting with postauricular swelling, pain, and fever, following a history of acute or chronic otitis media. Imaging studies, such as CT scans, confirming the presence of a subperiosteal collection over both mastoid bones, support its use.

• Ensure documentation specifies "bilateral" involvement; otherwise, use the appropriate unilateral code.
• Always code the underlying cause, such as acute or chronic otitis media, as a primary diagnosis if still present.
• Differentiate from mastoiditis without abscess or other types of mastoid abscesses (e.g., intracranial).