(See also Overview of Idiopathic Interstitial Pneumonias Overview of Idiopathic Interstitial Pneumonias Idiopathic interstitial pneumonias are interstitial lung diseases that have no known cause that have some similarities in symptoms and how they affect the lungs. Some types of these diseases... read more .)
Respiratory bronchiolitis-associated interstitial lung disease and desquamative interstitial pneumonias are types of idiopathic interstitial pneumonia. They have many similarities, so some experts think they may be part of the same disorder. However, desquamative interstitial pneumonia is often more severe. Both disorders primarily affect cigarette smokers in their 30s and 40s. Men are affected more often than women (ratio of almost 2:1).
Some people develop a cough. Most people develop shortness of breath with even minimal exertion.
Diagnosis
Chest computed tomography
In people with either disorder, a chest x-ray shows less severe changes than in idiopathic pulmonary fibrosis Idiopathic Pulmonary Fibrosis Idiopathic pulmonary fibrosis is the most common form of idiopathic interstitial pneumonia. Idiopathic pulmonary fibrosis affects mostly people over the age of 50, usually former smokers. People... read more and may show no changes in up to 20% of people. Chest computed tomography (CT) also shows lung changes. Pulmonary function testing Pulmonary Function Testing (PFT) Pulmonary function tests measure the lungs' capacity to hold air, to move air in and out, and to absorb oxygen. Pulmonary function tests are better at detecting the general type and severity... read more 
shows a decline in the amount of air contained in the lungs. The amount of oxygen in a blood sample is low.
A lung biopsy is often needed to confirm the diagnosis.
Treatment
Smoking cessation
Although doctors cannot always predict how the disorders progress over time, the prognosis for both is good when people stop smoking.
Smoking cessation Smoking Cessation While often very challenging, quitting smoking is one of the most important things smokers can do for their health. Quitting smoking brings immediate health benefits that increase over time... read more is the key treatment. Some doctors give corticosteroids or cytotoxic drugs (such as azathioprine or cyclophosphamide) because they may be effective in other interstitial lung diseases, but the effectiveness for these diseases is unknown.
