In addition, the sweat is very salty, and the child may suffer from salt depletion while sweating during hot weather. Children with cystic fibrosis suffer repeated pulmonary infections, and in time the lungs of most patients are infiltrated with Pseudomonas bacteria, an infectious agent very difficult to eradicate. Fever, cough, difficulty in breathing, fast respiration, flaring of the nostrils, poor appetite, and reduced activity are typical features of acute cystic fibrosis. Lung collapse, excessive mucus in the bronchi, or abscesses are possible. Sometimes, because of the air that is chronically trapped in the chest, the child gets a barrel-chested appearance.
Cystic fibrosis is diagnosed with a sweat test, which measures the amount of salt in perspiration.
If that test is positive, it should be confirmed with a second test. Since a child's siblings run an increased risk of also having cystic fibrosis, they should also be tested. Surgery is sometimes performed to correct physical complications. Because some of the tenacity of the mucus and secretions results from increased amounts of DNA, a new approach is the administration of Pulmozyme, which contains an enzyme that breaks down the DNA, thereby liquefying the secretions and making it easier to clear them. Scientists have recently isolated the gene responsible for cystic fibrosis and have begun developing treatment techniques that will repair the genetic defect in a patient's lung tissue.