Subperiosteal abscess of mastoid, right ear

This code signifies an infection that has formed a collection of pus beneath the periosteum (the membrane covering the bone) of the mastoid process, specifically in the right ear. This condition is typically a complication of acute mastoiditis, where the infection has spread beyond the mastoid air cells.

Apply this code when documentation clearly indicates a subperiosteal abscess of the mastoid bone affecting the right ear. This diagnosis is often supported by imaging studies (e.g., CT scan) showing a fluid collection in this specific anatomical location, along with clinical signs of infection and right ear pain.

• Ensure laterality is explicitly documented as "right ear" to support this specific code.
• Distinguish from simple mastoiditis (H70.00-) or other types of mastoid abscesses (e.g., H70.09- for unspecified).
• Consider co-reporting with codes for the underlying cause, such as acute otitis media, if applicable and documented.