system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 22-year-old man presents to his physician with a chronic cough which he has had for the last five years. He mentions that his cough is usually productive; however, sometimes it is dry. His past medical records show seven episodes of sinusitis over the last two years and two episodes of community acquired pneumonia. He is a non-smoker and there is no history of long-term exposure to passive smoking or other airway irritants. There is no family history of an allergic disorder. On physical examination, his vital signs are stable. General examination shows mild clubbing of his fingers and examination of his nasal turbinates reveals nasal polyps. Auscultation of his chest reveals crackles and scattered wheezing bilaterally. A high-resolution computed tomography (HRCT) of the chest shows dilated, “tram track” bronchi, predominantly involving upper lung fields. Which of the following is the next best step in the diagnostic evaluation of the patient?
assistant
Measurement of sweat chloride levels