Infectious bronchiolitis refers to subtype of bronchiolitis where there is an definite infective precipitant. It falls under the sub group in inflammatory bronchiolitides and by some authors is considered a type of cellular bronchiolitis 3. It tends to be more clinically severe in children than adults.
It is characterized histologically by a pattern of acute bronchiolar injury, with epithelial necrosis and inflammation of the bronchiolar walls and intraluminal exudates. There can also be oedematous change and fibrosis within bronchiolar walls.
- respiratory syncytial virus (RSV): particularly in children (RSV bronchiolitis)
- bacterial species
- mycobacterial species
- Mycobacterium tuberculosis: see pulmonary manifestations of tuberculosis
- atypical mycobacterial species
- fungal species, e.g. Aspergillus fumigatus, particularly in immunocompromised patients
CT (HRCT) chest
Intense bronchiolar mural inflammation of cellular bronchiolitis results in centrilobular nodules that are usually associated with the tree-in-bud pattern 1. There can also be presence of bronchiolar wall thickening.
- 1. Pipavath SJ, Lynch DA, Cool C et-al. Radiologic and pathologic features of bronchiolitis. AJR Am J Roentgenol. 2005;185 (2): 354-63. AJR Am J Roentgenol (citation) - Pubmed citation
- 2. Costabel U, Bois RM, Egan JJ. Diffuse Parenchymal Lung Disease. S Karger Ag. (2007) ISBN:380558153X. Read it at Google Books - Find it at Amazon
- 3. Webb WR, Higgins CB. Thoracic Imaging, Pulmonary and Cardiovascular Radiology. (2010) ISBN:1605479764. Read it at Google Books - Find it at Amazon
- 4. Bierry G, Boileau J, Barnig C et-al. Thoracic manifestations of primary humoral immunodeficiency: a comprehensive review. Radiographics. 2009;29 (7): 1909-20. doi:10.1148/rg.297095717 - Pubmed citation