Interstitial Lung Disease

Interstitial lung disease (ILD) is a broad category of lung diseases that includes more than 130 disorders characterized by scarring (i.e. "fibrosis") and/or inflammation of the lungs. ILD accounts for 15% of the cases seen by pulmonologists (lung specialists). Some of the disorders included under the heading of ILD are:

• Idiopathic pulmonary fibrosis
• Connective tissue or autoimmune disease-related pulmonary fibrosis
• Hypersensitivity pneumonitis
• Sarcoidosis
• Eosinophilic granuloma (a.k.a. Langerhan's cell histiocytosis)
• Chronic eosinophilic pneumonia
• Wegener's granulomatosis
• Idiopathic pulmonary hemosiderosis
• Bronchiolitis obliterans
• Lymphangioleiomyomatosis

What are Common Symptoms of ILD?

• Shortness of breath with exercise and a
• Non-productive cough

These symptoms are generally slowly progressive, although rapid worsening can also occur. Some people also may have a fever, weight loss, fatigue, muscle and joint pain, and abnormal chest sounds, depending upon the cause.

What Happens in the Lungs With ILD?

In ILD, the tissue in the lungs becomes inflamed and/or scarred. The interstitium of the lung includes the area in and around the small blood vessels and alveoli (air sacs) where the exchange of oxygen and carbon dioxide takes place. Inflammation and scarring of the interstitium disrupts this tissue and leads to a decrease in the ability of the lungs to extract oxygen from the air.

The progression of ILD varies from disease to disease and from person to person. It is important to determine the specific form of ILD in patients because what happens over time and the treatment may differ depending on the cause. Importantly, each person responds differently to treatment and close monitoring during treatment is important.