What are interstitial lung diseases?
Interstitial lung diseases (ILD) are named after the tissue between the air sacs of the lungs called the interstitium. In these diseases the interstitium is affected by scarring (fibrosis).
The symptoms and course of these diseases may vary from person to person, but the common link between the many forms of ILD is that they all begin with inflammation.
What are some of the rare disorders that fall under interstitial lung diseases?
- Acute interstitial pneumonia/pneumonitis
- Alveolar capillary dysplasia
- Alveolar hemorrhage syndromes (pulmonary capillaritis , acute idiopathic pulmonary hemorrhage of infancy, and idiopathic pulmonary hemosiderosis)
- Aspiration associated lung disease
- Autoimmune or rheumatologic related lung disease
- Bone marrow transplant associated lung disease/Graft versus host lung disease
- Bronchiolitis obliterans
- Cryptogenic organizing pneumonia formerly known as bronchiolitis obliterans organizing pneumonia (BOOP)
- Desquamative interstitial pneumonia
- DNA repair disorders
- Drug induced lung disease
- Eosinophilic pneumonias
- Follicular Bronchiolitis
- Growth abnormalities
- Hypersensitivity pneumonitis
- Immune mediated lung disease
- Immunocompromised host associated lung disease
- Lymphocytic interstitial pneumonia
- Lysosomal storage disorders
- Neuroendocrine Hyperplasia of Infancy (NEHI)
- Nonspecific interstitial pneumonia
- Pulmonary Alveolar Proteinosis
- Pulmonary Interstitial Glycogenosis (PIG)
- Pulmonary alveolar microlithiasis
- Pulmonary histiocytosis
- Pulmonary lymphagiectasia
- Pulmonary lymphangiomatosis
- Pulmonary vascular disorders
- Pulmonary sarcoidosis
- Radiation induced lung disease
- Surfactant gene mutation associated lung disease (SP-B, SP-C, ABCA3, TTF-1, GMCSF receptor).
How does interstitial lung disease affect the lungs?
- Lung tissue is damaged in some known or unknown way
- The walls of the air sacs in the lungs become inflamed
- Scarring (fibrosis) starts in the interstitium.
Fibrosis leads to permanent loss of your lung tissue’s ability to carry oxygen. The air sacs, as well as the lung tissue around the air sacs and the lung capillaries, are destroyed by the formation of scar tissue.
The diseases may run a gradual course or a rapid course. People with ILD may notice variation in symptoms, from very mild to moderate to very severe. The condition may stay the same for a long time or it may change quickly. The course of ILDs is unpredictable. If they progress, the lung tissue thickens and becomes stiff, and breathing becomes more difficult.
What causes interstitial lung diseases?
The cause of interstitial lung disease (ILD) is not known. Major contributing factors are smoking and inhaling environmental or occupational pollutants, such as inorganic or organic dusts. Other contributing factors include:
- Certain drugs or medications
- Radiation treatment
- Certain connective tissue or collagen diseases and sarcoidosis
- Family history.
What are the symptoms of interstitial lung diseases?
The following are the most common symptoms for interstitial lung diseases. However, each person may experience symptoms differently. Symptoms may include:
- Shortness of breath, especially with activity
- Dry, hacking cough that does not produce phlegm
- Extreme tiredness (fatigue) and weakness
- Loss of appetite
- Unexplained weight loss
- Discomfort in the chest
- Labored breathing, which may be fast and shallow
- Bleeding (hemorrhage) in the lungs
The symptoms of interstitial lung diseases may resemble other lung conditions or medical problems. Consult a health care provider for a diagnosis.
How are interstitial lungs diseases diagnosed?
In addition to a complete medical history and physical exam, the health care provider may also request the following tests:
Pulmonary function tests (PFTs)
Pulmonary function tests (PFTs) help to measure the lungs’ ability to move air into and out of the lungs. The tests are usually done with machines into which you breathe, and may include the following:
A spirometer is a device used to assess lung function. Spirometry, the evaluation of lung function with a spirometer, is one of the simplest, most common PFTs.
Peak flow monitoring (PFM)
This device is used to measure the how fast you can blow air out of the lungs. ILD-related changes can cause the large airways in the lungs to slowly narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled.
An X-ray is a picture of the inside of your child’s body, and is the most frequently used form of medical imaging. X-rays are painless, fast and easy to obtain.
Arterial blood gas may be done to check the amount of carbon dioxide and oxygen in the blood. Other blood tests may be used to look for possible infections.
High-resolution computed tomography scan (HRCT, CT, or CAT scan)
An imaging procedure that uses a combination of X-rays and computer technology to produce sharp, detailed horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. HRCT scans are more detailed than regular X-rays.
This is direct exam of the main airways of the lungs (bronchi) using a flexible tube called a bronchoscope. Bronchoscopy helps to evaluate and diagnose lung problems, assess blockages, take out samples of tissue or fluid, and help remove a foreign body. Bronchoscopy may include a biopsy or bronchoalveolar lavage.
Removing cells from the lower respiratory tract to help identify inflammation and exclude certain causes.
Removing a small piece of tissue from the lung so it can be examined under a microscope.
How are interstitial lung diseases treated?
There is no cure for interstitial lung disease (ILD). Treatments are aimed at preventing more lung scarring, managing symptoms, and helping you stay active and healthy. Treatment can’t fix lung scarring that has already occurred. Treatments may include:
- Oral medications to reduce inflammation and to suppress the immune system
- Pulmonary rehabilitation
- Oxygen therapy, from portable containers
- Lung transplant.
Key points about interstitial lung diseases
- Interstitial lung disease (ILD) includes more than 100 ongoing (chronic) lung disorders that are not caused by cancer or infection.
- The cause of ILD is not known. Major contributing factors are smoking and inhaling environmental or occupational pollutants.
- The most common symptoms of ILD are shortness of breath, especially with activity, and a dry, hacking cough.
- Tests that help measure the lungs’ ability to exchange oxygen and carbon dioxide are used to diagnose ILD. Blood tests and imaging tests may also be used to see how severe the problem is and monitor it over time.
- The goal of treatment for people with ILD is to prevent more scarring and manage symptoms.