Sweat testing infants detected by cystic fibrosis newborn screening

UMMS Affiliation

Department of Pediatrics; New England Newborn Screening Program



Document Type


Medical Subject Headings

Age Factors; Algorithms; Chlorides; Cystic Fibrosis; DNA Mutational Analysis; Decision Trees; Early Diagnosis; False Negative Reactions; False Positive Reactions; Follow-Up Studies; Humans; Infant, Newborn; Iontophoresis; Linear Models; Massachusetts; Muscarinic Agonists; Neonatal Screening; Patient Selection; Pilocarpine; Reference Values; Referral and Consultation; Risk Factors; Sweat


Allergy and Immunology | Pediatrics | Respiratory Tract Diseases


OBJECTIVE: Describe and define limitations of early pilocarpine iontophoresis (sweat testing) for cystic fibrosis (CF) newborn screening (NBS).

STUDY DESIGN: Population-based results from follow-up of CF NBS-positive newborns.

RESULTS: Insufficient quantity of sweat is more likely if the sweat test is done too early, but testing is generally successful after 2 weeks of age. Sweat chloride levels drop over the first weeks of life. CF carriers have higher sweat chloride concentrations than non-carriers.

CONCLUSIONS: Sweat testing can be performed effectively after 2 weeks of age for CF NBS-positive newborns. Earlier testing has a higher risk of insufficient sweat for completing testing.

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Citation: J Pediatr. 2005 Sep;147(3 Suppl):S69-72. Link to article on publisher's site

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