Causes of ILD

The causes of interstitial lung disease (ILD) fall into four general categories.

1. Autoimmune,connective tissue disease or other systemic disorders

Some autoimmune diseases that can cause ILD are:[TA2] 

• Scleroderma (systemic sclerosis)
• Rheumatoid Arthritis  (RA)
• Polymyositis/Dermatomyositis
• Large, medium or small vessel vasculitis
• Inflammatory bowel disease (IBD) 

Other systemic disorders that can cause ILD are:

• Common variable immunodeficiency disorder (CVID)
•  Sarcoidosis

2. Exposure to an agent that damages the lungs

For example, ILD can be caused by workplace exposure to inorganic dust — asbestos, silica or hard metal dust. Mold, bacteria or bird proteins are examples of organic dusts that can cause ILD. Smoking can cause ILD. Medications used to treat another condition such as chemotherapy drugs, amiodarone or nitrofurantoin, are examples of drugs that have been linked to ILD.

3. Genetics

Multiple members of one family may develop ILD, and some of these cases have been tracked to a single set of genes. Some inherited diseases are known to cause ILD. Examples include Hermansky-Pudlak Syndrome and Tuberous Sclerosis Complex.

4. “Idiopathic”

Meaning the cause is unknown.