CF Care Guidelines - Diagnosis

Diagnosing cystic fibrosis (CF) is a multi-step process. Today, that process often begins with a newborn screening test at birth. However, some people with CF are diagnosed as adults. Most people with CF are diagnosed quickly, although in some cases the diagnosis is not clear.

On this page:

• CF Diagnosis
• Sweat Testing
• Newborn Screening
• CFTR Metabolic Syndrome (CRMS)

CF Diagnosis

To help standardize the way people are diagnosed with CF and the steps leading to a diagnosis, the Foundation worked with CF medical experts to develop guidelines on:

• Newborn screening
• When to do sweat testing
• How to do sweat tests
• What to do if a sweat test is positive
• When to do genetic testing
• Providing families with information about a positive CF diagnosis and genetic counseling

Care Guidelines

• “Guidelines for Diagnosis of Cystic Fibrosis in Newborns through Older Adults: Cystic Fibrosis Foundation Consensus Report”
  J Pediatr 2008;153:S4-S14

Information and Resources for People with CF and their Familes

• "Testing for Cystic Fibrosis" - Information about the different tests for CF.
  
  
• "An Introduction to Cystic Fibrosis for Patients and Families" - A book for people newly diagnosed with CF and their families. To obtain a hard copy and accompanying DVD by U.S. mail, send an e-mail to info@cff.org.

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Sweat Testing

Cystic fibrosis is usually diagnosed through a sweat test. This test measures the salt content in sweat. A high salt level indicates CF.

If an infant has a positive newborn screen for CF during a newborn screening test, or if a person shows symptoms of CF, a doctor may order a sweat test. This simple, painless test is the best way to diagnose CF.

The Foundation and a committee of CF experts created a set of guidelines to ensure accurate sweat test results. The guidelines discuss:

• How to do a reliable sweat test
• Ways to make sure results are accurate
• How to reduce uncertainty

Care Guidelines

• “Diagnostic Sweat Testing: The Cystic Fibrosis Foundation Guidelines” 
  J Pediatr 2007;151:85-9

Information and Resources for People with CF and their Familes

• "The Sweat Test" - Questions and answers about the sweat test.
  
  
• "Cystic Fibrosis Foundation: Sweat Test" - A video on the CF Foundation's YouTube channel that explains a sweat test and shows how it is done.

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Newborn Screening

Most newborns in the United States are screened for cystic fibrosis at birth via newborn screening. The Foundation gathered experts to develop guidelines for CF newborn screening. The guidelines discuss:

• Developing a screen that finds the infants most likely to have CF
• Avoiding sweat tests for infants less likely to have CF
• Contacting the family doctor and the family with newborn screening results
• Counseling families and discussing next steps

Care Guidelines

• “Guidelines for Implementation of Cystic Fibrosis Newborn Screening Programs: Cystic Fibrosis Foundation Workshop Report” 
  Pediatrics 2007;119:e495-e518

Information and Resources for People with CF and their Familes

• "Newborn Screening" - Information about CF newborn screening.
  
  
• "My Baby Is a CF Carrier" - Information for parents whose newborn is a CF carrier.
  
  
• "My Baby Had an Abnormal Test" - Information for parents whose newborn was screened for CF and needs further testing.
  

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CFTR Metabolic Syndrome (CRMS)

The results of a newborn screening test may be uncertain, meaning the infant may or may not have CF. The Foundation provides care guidelines on how best to care for infants with an unclear newborn screening test. The guidelines cover:

• Diagnosing CRMS
• Working with primary care provider
• Recommendations for a CF clinic visit
• Periodic exams for CF signs or symptoms
• Importance of immunizations, including the influenza vaccine for babies at least 6 months old

Care Guidelines

• "Cystic Fibrosis Foundation Practice Guidelines for the Managment of Infants with Cystic Fibrosis Transmembrane Conductance Regulator-Related Metabolic Syndrome During the First Two Years of Life and Beyond"
  J. Pediatr. 2009 Dec;155(6)Suppl:S106-S116. Ref#YMPD41

Information and Resources for People with CF and their Familes

• "CFTR-Related Metabolic Syndrome" - Information for parents about CRMS.

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Updated 3/3/2011