Idiopathic constrictive bronchiolitis with rapidly progressive bronchiectasis and Mycobacterium kansasii infection

Constrictive bronchiolitis results in airways obstruction with progressive lung hyperinflation causing dyspnea and eventual respiratory failure. There are many known causes including rheumatic diseases, infections and toxic inhalations. We describe a 58-year-old man with no preexisting lung disease who suffered rapid loss of lung function with hyperinflation over months in association with rapidly progressive radiographic bronchiectasis. Airway cultures grew Mycobacterium kansasii, Pseudomonas aeruginosa and Aspergillus fumigatus; lung biopsy showed constrictive bronchiolitis that was clinically idiopathic. His respiratory symptoms and pulmonary function rapidly improved within a week of high-dose corticosteroid therapy. We suggest that a diagnosis of constrictive bronchiolitis should be considered in patients with a combination of new rapidly progressive lung hyperinflation and worsening bronchiectasis. We hypothesize that the bronchiolitis-associated bronchiectasis may occur from a predisposition for secondary infections known to cause large airway wall damage. Identification and adequate treatment of these infections is critical if concurrent high-dose corticosteroid therapy is attempted to alleviate the constrictive bronchiolitis.