Challenging respiratory infections in cystic fibrosis

To the Editor: We report a case of a 13-year-old girl with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa lung infection who developed an unusual infection that was challenging to manage. At a regular review, and with no obvious change in clinical respiratory status, the patient’s forced expiratory volume in 1 second (FEV1) was 70% of the predicted value — a drop from her usual 90%. A subsequent 3-week admission, including treatment with standard antipseudomonal antibiotics, physiotherapy and addition of nebulised dornase alfa, did not significantly improve her lung function. She was discharged home on a trial of azithromycin. One month later, she had a non-productive cough, and a bronchoalveolar lavage specimen showed no growth on culture.