A patient can be diagnosed with cystic fibrosis if certain findings are present.
Criteria for the diagnosis of cystic fibrosis - both of the following:
(1) one or more of the following:
(1a) positive newborn screen for elevated serum immunoreactive trypsinogen
(1b) first degree relative with cystic fibrosis
(1c) signs and symptoms seen with cystic fibrosis (see below)
(2) one or more of the following:
(2a) elevated sweat chloride concentration (>= 60 mmol/L)
(2b) biallelic CFTR CF causing variants on molecular genetic testing
(2c) nasal transmembrane epithelial difference measurement consistent with cystic fibrosis
Signs and symptoms suggestive of CF may include:
(1) nasal polyposis
(2) bronchiectasis and/or recurrent pneumonia
(3) chronic cough
(4) digital clubbing
(5) respiratory infection with Pseudomonas aeruginosa or atypical Gram-negative bacteria
(6) allergic bronchopulmonary dysplasia
(7) failure to thrive, poor weight gain, or growth deficiency
(8) recurrent pancreatitis
(9) exocrine pancreatic insufficiency with fat malabsorption and steatorrhea
(10) meconium ileus
(11) rectal prolapse
(12) distal intestinal obstructive syndrome
(13) protracted neonatal jaundice
(14) biliary cirrhosis
(15) obstructive azoospermia
(16) hyponatremia with salt losing syndrome
(17) metabolic alkalosis with hypochloremia and hypokalemia
(18) malnutrition with deficiency in fat-soluble vitamins (A, D, E and K)
