Diffuse panbronchiolitis, also referred as diffuse Asian panbronchiolitis, is an idiopathic progressive inflammatory small airways obstructive lung disease.
There is a striking predilection in the population from East Asia (e.g. Japan, Korea, China). It tends to present around the 3rd to 6th decade and often in nonsmokers. There is a higher prevalence in males with an M:F ratio of ~ 2:1.
It is most likely associated with infections such as H. influenza, P. aeruginosa, and type 1 human T-lymphotropic virus in genetically susceptible people.
Diffuse panbronchiolitis is characterized by centrilobular peribronchiolar infiltrates of acute and chronic inflammatory cells, which occur principally at the level of the respiratory bronchioles. There can be bronchiolar dilatation and intra-luminal inflammatory exudates.
Histologically, so-called "diffuse panbronchiolitis unit lesion" is comprised of foamy macrophages and lymphoid infiltrates.
Nonspecific and may show bilateral, diffuse, and small nodular shadows with pulmonary hyperinflation.
A peripherobasilar predilection may be present. Features are generally non-specific and include:
- centrilobular opacities with branching lines (tree-in-bud pattern 4)
- basal predominant bronchiolectasis
- mosaic attenuation with expiratory air trapping
Treatment and prognosis
Often treated with long-term low dose erythromycin. If untreated the disease can progress and even lead to death.
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