Obliterative bronchiolitis

Obliterative bronchiolitis (OB), also known as bronchiolitis obliterans or constrictive bronchiolitis, is a type of bronchiolitis and refers to bronchiolar inflammation with submucosal peribronchial fibrosis associated with luminal stenosis and occlusions. OB should not be confused with bronchiolitis obliterans organising pneumonia (BOOP)

The condition is characterised by concentric luminal narrowing of the membranous and respiratory bronchioles as a result of submucosal and peribronchiolar inflammation and fibrosis without any intraluminal granulation tissue or polyps/polyposis. There is an absence of diffuse parenchymal inflammation.

It can result from number of causes:

Mnemonic: CRITTS

Recognised associations include:

Chest radiographic findings can be normal or, if abnormal, nonspecific. Some associated features include:

  • hyperinflation
  • attenuation of vascular markings
  • occasionally reticular or reticulonodular markings

On HRCT chest, there are often sharply defined, areas of decreased lung attenuation associated with vessels of reduced calibre. These changes represent a combination of air trapping and oligaemia. This combination can give a mosaic attenuation pattern. Other features include:

It was first described by A.C.Reynaud in 1835 8-9.


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Article information

rID: 11010
System: Chest
Synonyms or Alternate Spellings:
  • Bronchiolitis obliterans
  • Constrictive bronchiolitis
  • Bronchiolitis obliterans syndrome
  • Bronchiolitis obliterans syndrome (BOS)
  • Obliterative (constrictive) bronchiolitis
  • Obliterative bronchiolitis (OB)

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