Cystic fibrosis is an inherited disorder of the digestive and respiratory systems that most commonly occurs in Caucasian children. The disease affects the pancreas, which normally produces enzymes needed to break down food during digestion, and also affects the glands that secrete sweat and mucus. As a result, the child with cystic fibrosis is unable to digest fats, and the sweat becomes abnormally salty. In addition, the child's mucus becomes very thick and sticky, blocking the air passages to the lungs. Respiratory infections occur frequently, often with a cough and fever, making the lungs susceptible to pneumonia.
Malnutrition is common in children with cystic fibrosis, because few nutrients are absorbed.
The most common test for CF is called the sweat test . To collect the sweat, the area is covered with a gauze pad or filter paper and wrapped in plastic. After 30 to 40 minutes, the plastic is removed, and the sweat collected in the pad or paper is analyzed. Higher than normal amounts of sodium and chloride suggest that the person has cystic fibrosis. The sweat test may not work well in newborns because they do not produce enough sweat.