Genetic multisystem disease associated with abnormalities in salt and water transport across epithelial surfaces.
Age of onset of symptoms is often in early infancy; however, in milder cases, symptoms may not develop until later childhood. Implementation of newborn screening in the US and some other countries allows for early detection and treatment.
A sweat test is the most conclusive test for diagnosis and is performed in addition to genetic testing.
Respiratory disease treatment includes mucus thinners, airway clearance, and antibiotics.
Gastrointestinal disease is treated with supplemental pancreatic enzymes, calories, and fat-soluble vitamins to support growth and nutrition.
Although severely life-shortening, in the past 50 years average survival has increased dramatically to almost 40 years of age.
A range of new drugs are either in development or already approved for use by patients. This includes drugs that restore proper function of the defective protein that causes cystic fibrosis, and drugs that have a direct effect on mucociliary clearance.
Cystic fibrosis (CF) is a severely life-shortening genetic disease resulting from abnormalities in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel found in cells lining the lungs, intestines, pancreatic ducts, sweat glands, and reproductive organs. There are over 2000 known disease-causing mutations that interrupt various stages of CFTR synthesis and function. The most common clinical manifestations are pancreatic dysfunction, resulting in calorie malabsorption; and lung disease, resulting from a cycle of mucus retention, infection, and inflammation.
History and exam
Key diagnostic factors
- positive newborn screen
- failure to pass meconium
- failure to thrive
- voracious appetite
- wet-sounding cough
- recurrent infection
- chronic sinusitis
- genital abnormalities in males
Other diagnostic factors
- malabsorptive stool with steatorrhea
- digital clubbing
- gastroesophageal reflux
- increased anteroposterior (AP) diameter of the chest
- history of pancreatitis
- history of acute appendicitis
- enlarged liver or spleen
- family history of CF
- known carrier status of both parents
1st investigations to order
- sweat test
- immunoreactive trypsinogen (IRT) test (newborn screening)
- genetic testing
Investigations to consider
- sinus x-ray
- deep throat swab
neonates with meconium ileus/partial distal intestinal obstruction
complete intestinal obstruction or peritonitis
acute respiratory infection
asthma exacerbation without infection
- Primary ciliary dyskinesia
- Primary immunodeficiency
- Lung transplant referral for individuals with cystic fibrosis: Cystic Fibrosis Foundation consensus guidelines
- Cystic Fibrosis Foundation pulmonary guidelines: use of cystic fibrosis transmembrane conductance regulator modulator therapy in patients with cystic fibrosis
Cystic fibrosis: what is it?
Cystic fibrosis: what treatments work?More Patient leaflets
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer