4A41.2

ICD-11 MMS 2026-01

Inclusion body myopathy

Description

Inclusion body myopathy (IBM) is distinguished from polymyositis (PM) and dermatomyositis (DM) on the basis of clinical and histopathological features. A characteristic clinical phenotype is characterised by insidious onset of muscle weakness over months to years, muscle weakness localised predominantly in the thigh muscles and finger flexors, and resistance to glucocorticoid treatment. Typical histopathologic features include sarcoplasmic and nuclear inclusions and rimmed vacuoles.

Exclusions from above levels

  • 02 – Neoplasms
  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 20 – Developmental anomalies

Child codes

  • 4A41.20 – Inflammatory inclusion body myositis
  • 4A41.21 – Noninflammatory inclusion body myopathy
  • 4A41.2Z – Inclusion body myopathy, unspecified

Sibling codes

  • 4A41.0 – Dermatomyositis
  • 4A41.1 – Polymyositis
  • 4A41.Y – Other specified idiopathic inflammatory myopathy
  • 4A41.Z – Idiopathic inflammatory myopathy, unspecified

Foundation entity

Inclusion body myopathy – http://id.who.int/icd/entity/983668658

Part of: 4A41: Idiopathic inflammatory myopathy › 04: Diseases of the immune system