AB11.1

ICD-11 MMS 2026-01

Chronic mastoiditis

Description

Persistent or recurrent inflammation of the space in the mastoid bone. It is often a complication of otitis media.

Index terms

  • Chronic mastoiditis
  • chronic mastoiditis with opacification of mastoid
  • Chronic suppurative mastoiditis
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  • Fistula of mastoid
  • Postaural mastoid fistula
  • postaural fistula
  • postauricular fistula
  • Retroauricular fistula
  • Caries of mastoid
  • mastoid necrosis

Exclusions from above levels

  • 01 – Certain infectious or parasitic diseases
  • 02 – Neoplasms
  • 05 – Endocrine, nutritional or metabolic diseases
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  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 19 – Certain conditions originating in the perinatal period
  • 22 – Injury, poisoning or certain other consequences of external causes

Sibling codes

  • AB11.0 – Acute mastoiditis
  • AB11.2 – Petrositis
  • AB11.3 – Mastoiditis, unspecified as acute or chronic
  • AB11.Y – Other specified mastoiditis related conditions

Foundation entity

Chronic mastoiditis – http://id.who.int/icd/entity/1578692740

Allowed postcoordination axes

Part of: AB11: Mastoiditis or related conditions › 10: Diseases of the ear or mastoid process