Bronchiectasis

What it is

Bronchiectasis is a disorder of the major bronchi and bronchioles that is characterized by permanent abnormal dilatation and destruction of bronchial walls; it is also put as permanent dilation of the terminal bronchioles due to chronic infection. Its pathophysiology is the vicious cycle hypothesis: an initial infection leads to bronchial dilatation and airway destruction, which allows microbial colonization, mucus hypersecretion and obstruction, impaired mucociliary clearance and inflammation, which feeds the circle again.

Causes and risk

Causes divide into those that are more of localized disease and those that are more of diffuse or bilateral disease. The localized causes are post infectious (TB, pneumonia), obstructive (foreign body, tumor, hilar lymph node), chronic aspiration, and infection with non-tuberculus mycobacteria. The diffuse or bilateral causes are cystic fibrosis, primary ciliary dyskinesia, immunodeficiency such as common variable immunodeficiency, allergic bronchopulmonary aspergillosis in patients with asthma, connective tissue diseases such as Sjogren's and RA, and alpha1 antitrypsin deficiency.

A second page groups the causes another way. Congenital: Kartegner's syndrome, cystic fibrosis and hypogammaglobinemia (CVID). Infections: measles, TB, which gives mostly local bronchiectasis, aspergillosis and pertussis. Bronchial obstruction: tumor and foreign body. And a neuropathic group.