Bronchiolitis obliterans


Airway Disease



Biomedical References

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"Bronchiolitis obliterans characteristically presents with the insidious onset of a nonproductive cough and dyspnea 2 to 8 weeks after an acute respiratory illness or toxic exposure." [Murray, p. 1297] Bronchiolitis obliterans (BO) is inflammation and scarring of the terminal bronchioles first described in patients exposed to irritant gases. Causes include nitrogen dioxide, sulfur dioxide, Thionyl chloride, bromine, ammonia, sulfur mustard, and methyl isocyanate. [Asthma in the Workplace, p. 381-2] BO most commonly occurs as a complication of irritant gas inhalation (e.g., nitrogen dioxide, chlorine, phosgene, ozone, hydrogen sulfide, and sulfur dioxide). BO has also been reported in nylon-flock workers, textile workers (polyamide-amine dyes), and workers in microwave popcorn plants (diacetyl). [Ladou, p. 383] Chest x-ray findings are normal or show hyperinflation. Spirometry usually shows a mixed obstructive/restrictive defect. [Hendrick, p. 99] "The key HRCT findings described in constrictive obliterative bronchiolitis are; areas of parenchymal decreased attenuation giving rise to the so-called 'mosaic attenuation pattern', pulmonary vascular attenuation, bronchial wall thickening and dilatation and air trapping on expiratory CT." [Hendrick p. 497]


2-8 weeks


History; Spirometry; HRCT (High-resolution computed tomography); Open lung biopsy;

ICD-9 Code


Reference Link

NIOSH - Flavorings-Related Lung Disease

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