Cryptogenic organizing pneumonia overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Cryptogenic organizing pneumonitis is a rapidly developing pneumonia-like illness characterised by lung inflammation and scarring that obstruct the small airways and air sacs of the lungs (alveoli). Its name is derived from the fact that it closely mimics pneumonia infections. (The term COP is used in Europe and BOOP in North America.)

Bronchiolitis obliterans organizing pneumonia is an inflammation of the bronchioles and surrounding tissue in the lungs. BOOP is often caused by a pre-existing chronic inflammatory disease like rheumatoid arthritis. In cases where no cause is found, the disease is called cryptogenic organizing pneumonia.

The clinical features and radiological imaging resemble infectious pneumonia. However, diagnosis is suspected after there is no response to multiple antibiotics, and blood and sputum cultures are negative for organisms.