Interstitial Lung Disease (ILD) refers to a group of disorders characterized by scarring or inflammation of the tissue that surrounds and supports the air sacs in the lungs. The changes associated with ILD can gradually cause the lungs to become stiff over time, preventing the air sacs from expanding normally. This decreases the amount of oxygen that is absorbed by the lungs and transferred to the bloodstream.
While some cases of ILD are caused by a known source, a significant proportion of ILD cases are idiopathic, meaning that these diseases have no known cause. The most common known causes of ILD are:
- Autoimmune diseases such as lupus, rheumatoid arthritis, scleroderma, or sarcoidosis
- Exposure of the lungs to foreign substances such as bird dander or droppings, fungus or mold, and certain types of dust including asbestos, coal dust, cotton dust, or silica dust
- Certain medications, such as nitrofurantoin, sulfanomides, bleomycin, amiodarone, methotrexate, gold, infliximab, and etanercept
The most common types of idiopathic ILD are: