This patient’s presentation is suggestive of bronchiectasis. Bronchiectasis causes permanent destruction and abnormal dilation of the conducting bronchi or airways. Patients usually present with a chronic cough productive of mucopurulent and tenacious sputum, sometimes with dyspnea and wheezing. There is often a past history of repeated respiratory tract infections requiring antibiotics. Diagnosis is usually made clinically, along with high resolution computed tomography (HRCT) of the chest showing bronchial wall thickening and airway dilatation (see exhibit).
Patients with suggestive bronchiectasis on HRCT should undergo functional assessment by pulmonary function testing. Potential reversible causes (shown in the above table) should also be investigated. Current guidelines recommend complete blood count with differential, immunoglobulin quantitation (e.g., IgA, IgG, and IgM), and sputum culture and smear (bacteria, fungi, and mycobacteria) as the initial evaluation for bronchiectasis.
This patient has repeated infections and the culture grew an encapsulated organism. Common variable immunodeficiency should be suspected since it can present in adults without childhood infections. Immunoglobulin quantitation can identify these patients, and gamma globulin replacement can reduce further respiratory tract infections and lung injury.