Progressive thickening of the walls of the air sacs of the lungs, resulting in shortness of breath
Inflammation and thickening of the walls of the alveoli (air sacs) in the lungs is called fibrosing alveolitis. As a result of this condition, it is difficult for oxygen to pass into the bloodstream, and the level of oxygen in the blood falls. In addition, the alveoli begin to lose their elasticity, causing shortness of breath.
Usually, fibrosing alveolitis is a long-term disorder, developing over months or years. Rarely, an acute form develops rapidly over a few days or weeks. Both forms tend to become progressively worse and are difficult to treat successfully. The condition most commonly occurs in people over the age of 60 and is more common in men.
In some cases, fibrosing alveolitis is the result of an autoimmune disorder, in which the immune system attacks the body’s own healthy tissues. For example, the condition may be associated with rheumatoid arthritis or systemic lupus erythematosus. Other possible causes include radiotherapy of the organs in the chest and certain drugs that are used in the treatment of cancer (see Anticancer drugs). In about half of all cases, no cause can be found, and the condition is then known as idiopathic pulmonary fibrosis.
In long-term fibrosing alveolitis, symptoms worsen gradually over months or years. When the disorder has a sudden onset, they worsen over a few days. Symptoms may include the following:
Shortness of breath.
Persistent, dry cough.
As the condition progresses, breathing becomes increasingly difficult, especially during vigorous exercise. In severe cases, there is an increased risk of respiratory failure and chronic heart failure. Some people with the disorder are more susceptible to lung cancer (see Primary lung cancer).
Your doctor may suspect that you have fibrosing alveolitis from your symptoms and medical history and from listening to your chest with a stethoscope. You may have a chest X-ray or CT scanning to look for thickened lung tissue. Your doctor may also arrange for you to have a blood test to check the levels of oxygen and carbon dioxide in your blood (see Measuring blood gases) and lung function tests. A small sample of lung may be taken using a bronchoscope (see Bronchoscopy) to exclude other disorders. A positive diagnosis of fibrosing alveolitis may be made by taking a lung sample surgically.
Sometimes, fibrosing alveolitis remains stable for months or years and does not need treatment. In this case, it will be monitored regularly. If it is progressing, high-dose corticosteroids (see Corticosteroids for respiratory disease) combined with other immunosuppressant drugs may be used to suppress the immune system and slow the progress of the lung damage. These drug treatments are effective in only about 1 in 4 cases. Home oxygen therapy may be used to assist breathing, but the treatment has to be used for at least 15 hours a day.
Fibrosing alveolitis usually progresses, making breathing increasingly difficult. Only about half of those with the condition survive for longer than 5 years after diagnosis. For some people, a lung transplant may be life-saving. About 1 in 10 people with fibrosing alveolitis develops lung cancer.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.