Aspiration bronchiolitis

Aspiration bronchiolitis, or diffuse aspiration bronchiolitis, is a condition characterized by chronic inflammation of bronchioles caused by recurrent aspiration of foreign particles.

Epidemiology

Risk factors

Patients with esophageal conditions such as achalasia, Zenker diverticulum, or esophageal carcinoma are at risk for aspiration bronchiolitis.

Associations

• neurologic disorders: ~ 50% ³
• dementia: ~50% ³

Clinical presentation

The onset of aspiration bronchiolitis can be more insidious than aspiration pneumonia, and in half of the patients, episodes of aspiration can be unrecognised ³. Patients may have a chronic cough.

Pathology

It is characterized by a chronic inflammatory reaction to repeatedly aspirated foreign particles in the bronchioles.

Radiographic features

HRCT

Aspiration bronchiolitis may be seen as unilateral or bilateral foci of ^1,6:

• branching areas of increased attenuation with tree-in-bud change
• centrilobular nodules
• mottled, poorly-defined acinar areas of increased attenuation

Consolidation is not a major radiological finding.

Treatment and prognosis

A chronic cough in aspiration bronchiolitis usually does not respond to β-adrenergic bronchodilators or to inhaled steroids. Swallowing rehabilitation and temporary intravenous alimentation are considered the most effective ways to reduce the symptoms ⁷.

History and etymology

Diffuse aspiration bronchiolitis as distinct entity was thought to have been first proposed by T Mastuse et al. in 1996 ³.

Differential diagnosis

If features are diffuse consider:

• diffuse panbronchiolitis from another (non-aspiration) cause

As a broader differential on CT, consider other forms of bronchiolitis.

See also

• pulmonary aspiration syndromes