Bronchiolitis obliterans with organizing pneumonia (BOOP)

Bronchiolitis obliterans with organizing pneumonia (BOOP) is a rare lung condition in which the small airways (bronchioles) and the tiny air-exchange sacs (alveoli) become inflamed and plugged with connective tissue. The disorder is also known as cryptogenic organizing pneumonia (COP).

In some people, bronchiolitis obliterans with organizing pneumonia causes no signs or symptoms. Most people who have BOOP experience a persistent nonproductive cough and — depending on how much of the lung is affected — shortness of breath with exertion.

Some forms of bronchiolitis obliterans with organizing pneumonia are associated with other health problems, such as:

• Infections. BOOP sometimes occurs after people have had certain infections, including chlamydia, influenza or malaria.
• Inflammatory disorders. The risk of BOOP appears to be heightened for people who have disorders such as lupus, rheumatoid arthritis or scleroderma.
• Cancer treatment. People who have received certain types of chemotherapy or radiation to their chest sometimes develop BOOP.
• Transplanted tissue. Bone marrow, lung, kidney and stem cell transplants sometimes trigger bronchiolitis obliterans with organizing pneumonia.
• Drug exposure. Drugs that have been linked to BOOP include cocaine, gold salts and some antibiotics and anti-seizure medications.

Most people recover after weeks or months of treatment with a steroid such as prednisone. But in some people, BOOP can progress in spite of treatment.