What is the definition of Bronchiolitis Obliterans?

Bronchiolitis obliterans is an inflammatory condition that affects the lung's tiniest airways, the bronchioles. In affected people, the bronchioles may become damaged and inflamed leading to extensive scarring that blocks the airways. Signs and symptoms of the condition include a dry cough; shortness of breath; and/or fatigue and wheezing in the absence of a cold or asthma. Many different chemicals (such as nitrogen oxides, ammonia, welding fumes or food flavoring fumes) and respiratory infections can cause lung injury that leads to bronchiolitis obliterans. It can also be associated with rheumatoid arthritis and graft-versus-host disease following a lung or hematopoietic cell transplantation. While there is no way to reverse the disease, treatments are available that may stabilize or slow the progression. Another similarly named disease, bronchiolitis obliterans organizing pneumonia, is a completely different disease.

What are the alternative names for Bronchiolitis Obliterans?

  • Obliterative bronchiolitis

What are the causes for Bronchiolitis Obliterans?

Bronchiolitis obliterans may result from lung injury caused by a variety of different chemicals and respiratory infections. Inhaled chemicals known to irritate the lungs and lead to the condition include chlorine; ammonia; oxides of nitrogen or sulfur dioxide; welding fumes; or food flavoring fumes (such as diacetyl). Respiratory infections caused by respiratory syncytial virus, adenovirus, or Mycoplasma pneumonia have been linked with the condition. Bronchiolitis obliterans can also be associated with rheumatoid arthritis and graft-versus-host disease following a lung or hematopoietic cell transplantation.

What are the symptoms for Bronchiolitis Obliterans?

Signs and symptoms of bronchiolitis obliterans generally develop approximately two to eight weeks after exposure to toxic fumes or a respiratory illness. Affected people may experience a dry cough, shortness of breath, and/or wheezing. Fatigue and wheezing in the absence of a cold or asthma may also be noted. Symptoms generally progress slowly over weeks to months.

What are the current treatments for Bronchiolitis Obliterans?

Although there is no cure for bronchiolitis obliterans, treatment may help stabilize or slow its progression. The best treatment options and the effectiveness of the selected treatments vary based on the underlying cause and the severity of the condition. Medications often prescribed to people with bronchiolitis obliterans include certain types of antibiotics (called macrolide antibiotics), corticosteroids, and immunosuppressive drugs. In severe cases, lung transplantation may be recommended. Therapies such as cough suppressors or supplemental oxygen can also be given to manage the symptoms associated with the condition.

How is Bronchiolitis Obliterans diagnosed?

A diagnosis of bronchiolitis obliterans is often suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to support and confirm the diagnosis. These tests may include:
  • Imaging studies (such as a chest CT scan)
  • Pulmonary function tests
  • Surgical lung biopsy (gold standard)

Is Bronchiolitis Obliterans an inherited disorder?

Bronchiolitis obliterans is not thought to be inherited. Most cases occur sporadically in people with no family history of the condition.