Bronchiolitis Obliterans in Children

What is Bronchiolitis Obliterans?

Bronchiolitis Obliterans (BO), also known as Obliterative Bronchiolitis (OB) is a chronic obstructive airflow syndrome which affects the small airways in the lungs, the bronchioles. The bronchioles conduct air from the large airways (bronchi) to the alveoli where oxygen enters the bloodstream.

What causes it?

Bronchiolitis obliterans (BO) is a rare and severe form of chronic obstructive lung disease in children that results in the lower respiratory tract, which occurs in a number of forms. Actually, any type of lower airway infection in children could potentially cause BO; however, the most common disease triggering BO is acute viral bronchiolitis. The actual causes of BO are varied, but can occur after certain infections (i.e. adenovirus), after a bone marrow or heart-lung transplant, with some types of connective tissue disorders; after inhalation from smoke or other irritants, or after a rare reaction to some medications.

How is it diagnosed?

A clinical diagnosis is made when after a severe viral bronchiolitis, or sometimes pneumonia with respiratory insufficiency, wheezing and hypoxemia persists for at least two months. The diagnosis of BO may be considered after a child has an episode of illness which is known to possibly cause it. If BO is suspected, a CT scan of your child’s lungs may be required, and oftentimes doctors may recommend that a biopsy be taken.

How is it treated?

Treatment of BO is difficult. There is no standardized drug regiment, although most experts start with oral steroids, such as prednisolone in the early stages. Steroids are anti-inflammatory drugs that help to decrease the inflammation that is damaging the small airways. In some children however, by the time the disease is diagnosed, the inflammation may have settled and the airways are left severely narrowed due to scarring.