Plastic bronchitis is the buildup of lymph fluid in the lungs. The fluid leaks into the airways and causes tree-like casts to form, blocking the airways. Treatment includes removing the casts and improving lymphatic flow to prevent respiratory failure.

Plastic bronchitis is a respiratory condition that occurs as a result of lymph fluid buildup in the lungs. When fluid doesn’t drain correctly, it leaks into the airways. This leads to the formation of casts that can block the airways and cause breathing difficulties and other symptoms.

If casts are large or numerous, they can lead to respiratory failure, which can be fatal. But for people with plastic bronchitis, treatment can help them keep their airways clear and lower the risk of repository failure.

This article provides an overview of this lung condition, how these casts form within your airway, and how treatment focuses on removing these casts to improve air flow. We’ll also share the medications that your doctor may consider to treat this condition.

Plastic bronchitis is a rare lung condition that’s a type of lymphatic flow disorder. A lymphatic flow disorder is any condition that involves irregular circulation of lymph fluid.

In plastic bronchitis, lymph fluid builds up in the airways. The fluid buildup leads to the formation of rubbery mucus plugs, also called casts, in the airways. This blocks the flow of air and makes it difficult to breathe. For some people with plastic bronchitis, these casts take the shape of tree branches.

plastic bronchitis castsShare on Pinterest
Medical Illustration by Maya Chastain

Plastic bronchitis is more common in children than in adults. Sometimes, the casts can block enough of a person’s airways for the condition to be life threatening. But treatment can help prevent respiratory failure.

The lymphatic system is a drainage network that’s part of your immune system. It runs throughout your body, and a fluid called lymph moves through it. Lymph is made up of all the excess protein and fluid that comes from body tissues.

When someone has plastic bronchitis, lymph doesn’t drain from their lungs the way it should. This causes it to collect in their lungs instead. The lymph fluid then leaks into the airways, where it forms the plastic bronchitis casts.

The symptoms of plastic bronchitis can vary depending on factors such as where in the airways the casts are located, the size of the casts, and how many casts there are. Symptoms can include:

The exact cause of plastic bronchitis is unclear. But there are some known risk factors linked to the condition. These include:

Doctors determine the diagnosis of plastic bronchitis based on symptoms, the results of a physical exam, and imaging tests.

There’s no single specific test for the condition.

But your doctor will likely want to listen to your breathing, check for any wheezing, and observe any coughing. They’ll then order imaging such as:

Imaging can look for damage caused by plastic bronchitis, such as a collapsed lung, as well as for the presence of casts in the airways.

There are several treatment options for managing plastic bronchitis. The treatment goal is to maintain open airways, manage lymphatic flow, and remove casts. This might include:

  • Bronchoscopy: A bronchoscopy can remove casts and clear the airway. In this procedure, a doctor will insert the scope through the mouth. They’ll use small tools to carefully remove the casts.
  • Corticosteroids: Doctors often prescribe these medications to lower inflammation. These medications can also help slow or block cast formation.
  • Antibiotics: These medications can slow down cast formation and treat any underlying infections.
  • Mucolytics: These are medications that can make it easier for someone to cough out the casts.
  • Lymphatic surgeries: Surgical options, such as lymphatic embolization, stent grafting, and duct ligation can help manage lymphatic flow to stop new casts from forming.
  • Breathing assistance and airway management: Sometimes, options such as supplemental oxygen can help restore blood oxygen levels for people with plastic bronchitis. When plastic bronchitis is severe, breathing tubes can be an option.

The life expectancy and outlook for someone with plastic bronchitis depend on various factors. These include the size and location of the casts and how soon treatment is received.

The condition has a mortality rate ranging from 6–60%. This means it’s best to talk with your doctor to get an accurate picture of your individual outlook and the factors affecting your life expectancy.

Plastic bronchitis is a serious condition caused by a buildup of lymph fluid in the lungs. When lymph fluid doesn’t drain correctly, it leaks into the airways where it forms casts. These casts can block the airways and cause breathing difficulties. They can also cause symptoms such as coughing, fever, and chest pain. If the airway blockage is severe, plastic bronchitis can be fatal.

Treatment can help keep airways clear and lower the risk of respiratory failure. Treatment usually includes the removal of casts through bronchoscopy, along with medications to reduce inflammation and improve lymphatic flow. Additional treatments, such as lymphatic surgeries and supplemental oxygen, might also be options.