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Cystic Fibrosis in Children

  • A genetic disorder affecting mucous movement in the respiratory, digestive and reproductive systems
  • Symptoms include difficulty breathing, losing weight, intestinal blockages
  • Medications and surgical procedures may be needed to help with digestive and respiratory health
  • Involves Cystic Fibrosis Program, Pediatrics, Pediatric Pulmonology, Allergy, & Immunology
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Cystic Fibrosis in Children


Because newborns across the United States are now screened for cystic fibrosis soon after they’re born, the condition is being diagnosed and treated earlier. Partially as a result of improved screening and early detection, and also because there are new and more effective treatments, many children with cystic fibrosis are now living longer, healthier lives. 

“We now identify children before they become symptomatic,” says Marie E. Egan, MD, director of Yale Medicine's Cystic Fibrosis Program and a pediatrician. “They do better in the long run if we can diagnose them before they get into trouble.” 

This genetic disorder, which primarily affects the respiratory, digestive and reproductive systems, can keep organs and systems from functioning properly and can lead to many complications. In the past, children may not have lived to their 20s, but now if the condition is managed well, they are living into their 50s.

What causes cystic fibrosis?

Cystic fibrosis is a genetic disorder. A child who has cystic fibrosis has received a mutated cystic fibrosis transmembrane conductance regulator (CFTR) gene from both parents.

“It’s what we call an autosomal recessive disorder, which means you have to inherit a copy of the gene that contains an error from both your mother and your father,” Dr. Egan says. “Most people say, ‘This doesn’t run in my family, so there’s no way my child could have it.’ But one in 25 people walking around, completely normal and with no symptoms, carry one copy of this gene that contains a mutation. It’s very common.”

When two carriers of the defective gene have a child, there’s a 25 percent chance their child will have cystic fibrosis. There are an estimated 2,000 different mutations in the gene that can cause the disease. In the United States, cystic fibrosis occurs in one out of every 3,500 live births. While the disease primarily affects Caucasians, people of any ethnic background can be born with the disease. 

How does cystic fibrosis affect the body?

The mutated gene that causes cystic fibrosis affects a protein that helps with salt regulation across cells. In addition to losing more salt through sweat than is normal, the mutation affects how salt and water move through channels in the body, leading to changes in mucus. (Parents of babies with cystic fibrosis often notice, when kissing their babies, that their skin tastes salty.)

Normally, mucus in the airways helps to move harmful bacteria or dust out of the lungs and also helps move waste through the intestines. In a person with cystic fibrosis, the mucus is very sticky and can’t facilitate this movement of particles. This leads to infections or blockages.

“Most of us just swallow a little bit of mucus and fluid all the time; it happens so seamlessly that we never even notice it,” Dr. Egan says. “But for someone with cystic fibrosis, it can feel like you are always sick. with lots of mucus to cough up.”

What are the potential complications of cystic fibrosis?

The disease can affect children in different ways, often depending on their specific gene mutation and how significantly each body system is affected. Primarily, cystic fibrosis can include the following systemic complications.

  • Respiratory system: Respiratory problems are the most common complications for people with cystic fibrosis and lung disease accounts for most of the early deaths associated with it. Especially common are infections and bronchiectasis, in which damaged airways struggle to move mucus up and out of the body. Chronic infections in the lungs are also a problem—patients have to be particularly careful in places where there may be an increased risk of catching an infection, such as healthcare waiting rooms. Risk of respiratory infection in people with cystic fibrosis increases with age. 
  • Digestive system: The gastrointestinal tract also is affected. The pancreas uses the CFTR protein to secrete bicarbonate (salt and water) to move chemicals that aid in digestion. This CFTR protein does not work in patients with cystic fibrosis, so they have difficulty digesting food properly. Because this can happen even in utero, some children with cystic fibrosis are born with an intestinal blockage that has to be addressed immediately. The disease also can prevent a child from absorbing all the nutrients the body needs, causing a failure to thrive. Additionally, it damages the pancreas and affects the organ’s other function, which is to produce insulin to regulate sugar. As a result, children with cystic fibrosis usually begin specialized testing for diabetes at 10 years of age.
  • Reproductive system: Another system that relies on mucus to work properly, the reproductive system, is also affected by cystic fibrosis. Complications are generally more serious for men, as the vas deferens, a vital tube in the system, can become blocked, leaving men infertile. The disorder can also affect the fertility of women, but it’s less common.

Other complications can occur in organs including the liver and gallbladder, and the sweat glands, which can severely affect salt losses from the skin. Sports drinks are recommended as a supplement during and after exercise to replenish salt losses from perspiration. 

What are the treatment options for cystic fibrosis?

As with the potential complications, the options for treatment will vary from person to person, but a key aspect is to ensure adequate nutrition. "We try to keep children growing, making sure they’re between the 50th and 75th percentile for weight and for height, which is a challenge for somebody whose pancreas isn’t working correctly," Dr. Egan says. 

Most of a child’s lung growth happens in the first two years of life, so it’s especially important for babies to grow well in those years  in order to have good, healthy lung reserve as they get older. Once they mature, people with cystic fibrosis start to lose a little function every year, so a good start is important.

Digestive health: Because the pancreas is usually affected, a person with cystic fibrosis will need help digesting food.  Most take pancreatic enzyme supplements (in the form of pills) every time they eat, which helps break down proteins, fats and complex carbohydrates.

Some babies with cystic fibrosis are born with an intestinal obstruction (meconium ileus). Usually, it can be corrected medically, but occasionally surgery may be required. When intestinal obstruction occurs later on in life it is called distal ileal obstruction (DIOS).

Some children need a gastronomy tube (G-tube) to ensure adequate nutrition. This is inserted surgically into the stomach and attached to an adaptor fitted to the child’s abdomen. It’s designed for long-term, direct, controlled feeding of liquid food provided by a doctor and administered by a parent.

People with cystic fibrosis usually take specialized vitamins, including A, D, E and K, because they’ll have trouble absorbing those through diet.

Respiratory health: Because babies with cystic fibrosis need help moving out their airway mucus, the first thing doctors often teach parents is how to use chest physiotherapy to help children expel mucus. The parent uses a hand-held percussor to tap on the baby’s chest in different positions. This helps loosen and move out anything in the airways.  Older children may use a special therapy vest; connected to a compressor, it vibrates at certain frequencies that help loosen up the mucus.

“Some children love chest physiotherapy and vest therapy, some children hate it,” Dr. Egan says. “But we have to figure out how to get everyone to tolerate it in order to get their mucus up and out.”

Children may also take specific medicines to help with healthy breathing. Often administered with a nebulizer, these include AccuNeb (albuterol, which up the airways), Pulmozyme (dornase alfa, which helps make the mucus less sticky), and hypertonic saline (which hydrates mucus to move it up and out).

Some kids may carry certain bacteria in their lungs that lead to recurrent infections. One such bacteria is known as pseudomonas. Pseudomonas is often treated with nebulized antibiotics to help fight the infection.

It can be difficult for parents of a child with cystic fibrosis to keep track of all the details (food, vitamins, keeping the airways clear) involved in helping the little one stay healthy, acknowledges Dr. Egan. 

“You can’t ever put it away,” she says. “There are lots of other diseases that you may have to take a pill in the morning and in the evening, but during the rest of the day, you can get a mental break from things, you don’t have to think about it. But for cystic fibrosis, one of the things that makes it tough is that you don’t really get that mental break.”

What makes Yale Medicine’s approach to treating cystic fibrosis unique?

Having cystic fibrosis can mean a lot of time spent with doctors, and Yale Medicine has developed ways to make sure that time is spent as efficiently as possible—and is a more comfortable experience for kids, too. One way is by mapping out appointments so families can see specialists at the Cystic Fibrosis Program on the same day, during the same visit. 

“As a team, we really try to coordinate so we can get all of those visits lumped together, so you miss one day of school as opposed to multiple days,” Dr. Egan says. “We understand that sometimes means you spend a long time when you come one day, but we try to make the most of that one school day you’re giving up.”

Yale Medicine also offers a Buddy Program, which pairs medical students with cystic fibrosis patients; visits scheduled for the same day as well. In addition to providing the child with yet another supportive relationship (a "buddy), this also gives students a better understanding of what it’s like to have a chronic illness. 

“They’re here just to support the child,” Dr. Egan says. “We try to match their interests, and it gives the child something like a big brother or big sister experience. So while all these adults want to talk, they have somebody who is really their buddy.”