Interstitial lung disease refers to a group of diseases that are chronic, nonmalignant, and noninfectious. These diseases are characterized by infiltration of inflammatory cells into the walls of the alveoli (the air sacs of the lungs). The infiltration causes abnormal scarring in the connective tissue that supports the alveoli. If the disease progresses, scarring develops to the point that the lungs may be destroyed.
The causes of most interstitial lung disorders are unknown.
These ailments generally affect people over 50 years of age.
Idiopathic pulmonary fibrosis is the most common diagnosis among patients presenting with interstitial lung disease. It is a chronic, noninfectious, nonmalignant disorder that causes progressive shortness of breath. Average duration of life after the onset of symptoms is 4 to 5 years, but many affected persons live much longer. Males and females are affected equally. The disorder commonly develops in the middle years of life but it can occur at any age.
The cause of idiopathic pulmonary fibrosis is unknown. Inhalation of certain toxins, autoimmune disease, and radiation may cause pulmonary fibrosis. Medications including bleomycin, busulfan, phenytoin, and nitrofurantoin may cause interstitial fibrosis.
A major consequence of the formation of abnormal scar tissue is impairment of the transfer of oxygen from the air to the blood. Thus, an affected person may notice fatigue, malaise, and shortness of breath, particularly in connection with exercise. Occasionally, a cough that produces no sputum, and a sensation of chest discomfort are also present.
The physician may suspect an interstitial lung disease based upon the symptoms and the sounds heard upon examination of the chest with a stethoscope.
A chest x-ray will probably be ordered with lung function tests, both of which generally reveal significant abnormalities.
A CT (computed tomography) scan may better demonstrate the extent of involvement within the lungs.
An open biopsy of the lung may be necessary to confirm the diagnosis. This is a surgical procedure, performed under general anesthesia, in which the chest wall is opened and a small sample of lung tissue is removed for examination under a microscope.
High doses of oral corticosteroids (e.g., prednisone) are the usual treatment. Cytotoxic drugs such as cyclophosphamide and azathioprine have also been used. The response to corticosteroids is better in patients with more inflammation and less fibrosis noted on lung biopsy.
Lung transplantation has been suggested for selected patients with end-stage pulmonary fibrosis.
The outlook for recovery is generally poor for occupational dust diseases and idiopathic (no-known cause) interstitial pulmonary fibrosis in which the lungs progressively stiffen.
What tests are needed to diagnose the condition?
Are there any risks associated with these tests?
How far has the disease progressed?
How serious is the condition?
What type of treatment will you be recommending?
How effective is this treatment?
Will you be prescribing any medications? What are the side effects?
What home measures can be taken to help slow down the disease?
If the disease progresses to a severe stage, would lung transplantation be a possibility?
What is the prognosis?