A 4-year-old girl presents with a complaint of fever, cough and shortness of breath for 2 days. Her mother tells you that she had pneumonia last year treated by antibiotics and recurrent episodes of diarrhea. On examination, her temperature is 101.3 F; respiratory rate is 30/min. and presence of purulent rhinorrhea. Auscultation of the chest reveals diminished breath sounds on the right side and wheezes in both lungs. Which is the most likely test to support the diagnosis of cystic fibrosis? A-Erythrocyte sedimentation rate B-Pulmonary function tests C-Liver function tests D-Sweat chloride test E-Rheumatoid factor Answer
