A 10-year-old child presents with history of chronic sinusitis and multiple nasal polypi. He also suffers from recurrent chest infections and malabsorption syndrome. Which one of the following tests would be useful for diagnosis?
Presence of chronic sinusitis, multiple nasal polypi and malabsorption point towards cystic fibrosis and therefore sweat chloride test would be useful.
Total IgE estimation
ESR
Level of angiotensin converting enzyme
Sweat chloride
Nose and PNS