L’atteinte bronchique dans la pneumopathie d’hypersensibilité

Hypersensitivity pneumonitis (HP) is a respiratory disease resulting from the inhalation of antigens to which the exposed subject was previously sensitized. HP is characterized by a diffuse and predominantly mononuclear cell inflammation of the alveolar regions that generally involves the small airways. Bronchiolitic lesions are well-described in histopathologic studies. This pathology explains the presence of mosaic attenuation and expiratory air trapping on thoracic scans. Chronic bronchitis with ventilatory obstruction and emphysema as a long-term outcome are possible consequences of this bronchial involvement.