[Bronchiectasis: diagnostic workup].

Bronchiectasis is a condition defined by permanent dilation of the bronchi, either idiopathic or associated with other disease states. Diagnostic workup for bronchiectasis is essential in determining management and treatment. For diffuse bronchiectasis, we propose a workup plan that includes testing for humoral immunodeficiency by measuring serum IgG and anti-pneumococcal antibodies, looking for primary ciliary dyskinesia by exhaled nasal NO and cytologic brush biopsy of the nasal mucosa, looking for cystic fibrosis by chloride sweat testing and genotyping, evaluation for allergic bronchopulmonary aspergillosis, and testing for alpha-1-antitrypsin deficiency. Workup studies should be guided by the patient's history and clinical context.