Clinical management of children and adults with cystic fibrosisBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6926.459 (Published 12 February 1994) Cite this as: BMJ 1994;308:459
- A K Webb,
- T J Davida
- North West Lung Centre, Wythenshawe Hospital, Manchester M23 9LT.
- a Monsall Hospital, Newton Heath, Manchester M10 8WR University of Manchester, Manchester
- Correspondence to: Dr
- Accepted 22 November 1993
The cystic fibrosis population is increasing by 120-140 patients a year, and by the year 2000 there could be 6000 patients in the United Kingdom, with equal numbers of adult and paediatric patients.1 It is hoped that better understanding of the underlying defect will be translated into practical treatment such as gene replacement, for at present the median survival for adults is only into the third decade.2 The review looks at the current management of cystic fibrosis.
The modes of presentation are listed (box 1) because some are not well known. Overdiagnosis remains a problem. In some parts of Britain up to 10% of patients referred to regional centres with cystic fibrosis are found to have an alternative diagnosis.3 The total absence of one or more of the major features - malabsorption due to pancreatic insufficiency, chronic suppurative lung disease, and failure to thrive - should lead to caution about the diagnosis. The main reasons for these errors are a disregard of the clinical features or the lack of them, incorrect performance of the sweat test, and faulty interpretation of the results of the test. Some patients (less than 10% seen in the United Kingdom, but up to 38% in one Canadian series), have sufficient pancreatic function for normal digestion, so that even the most sophisticated direct pancreatic function testing can exclude only pancreatic insufficiency and not cystic fibrosis itself. Homozygosity for one of the recognised gene deletions clearly indicates cystic fibrosis. Unfortunately, a cystic fibrosis mutation cannot be detected in about a fifth of patients; thus, negative results in the search for homozygosity of a cystic fibrosis gene does not exclude the diagnosis. In many cases, the final diagnosis still hinges on the accurate performance and correct interpretation of the sweat test.
Box 1 - Modes of presentation in cystic fibrosis
Well recognised modes of presentation in newborn infants
Prolonged neonatal …