Pulmonary Fibrosis

What is pulmonary fibrosis?

"Fibrosis" is a term used to refer to scarring, so pulmonary fibrosis means scarring in the lungs. Pulmonary fibrosis can be caused by many conditions, including chronic inflammatory processes (sarcoidosis, Wegener's granulomatosis), infections, environmental agents (asbestos, silica, exposure to certain gases), exposure to ionizing radiation (such as radiation therapy to treat tumors of the chest), chronic conditions (lupus, rheumatoid arthritis), and certain medications, such as nitrofurantoin and methotrexate.

In a condition known as hypersensitivity pneumonitis, fibrosis of the lungs can develop following a heightened immune reaction to inhaled organic dusts or occupational chemicals. This condition most often results from inhaling dust contaminated with bacterial, fungal, or animal products. Examples include silo fillers disease and pigeon breeders lung disease.

In some people, in fact in most cases, chronic pulmonary inflammation and fibrosis develop without an identifiable cause. Most of these people have a condition called idiopathic pulmonary fibrosis (IPF) that does not respond to medical therapy, while some of the other types of fibrosis, such as nonspecific interstitial pneumonitis (NSIP), may respond to immune suppressive therapy.

Other names for various types of pulmonary fibrosis that have been used in the past include chronic interstitial pneumonitis, Hamman-Rich Syndrome, usual interstitial pneumonitis (UIP) and diffuse fibrosing alveolitis.

What are pulmonary fibrosis symptoms?

Symptoms of pulmonary fibrosis include shortness of breath, coughing, and diminished exercise tolerance. The severity of symptoms and the worsening of symptoms over time can vary and are at least partially dependent upon the cause of the fibrosis.

How is pulmonary fibrosis diagnosed?

Pulmonary fibrosis is suggested by a history of progressive shortness of breath with exertion. Sometimes, during examination of the lungs with a stethoscope, the doctor can hear crackling sounds in the chest. The chest x-ray may or may not be abnormal, but a special x-ray test called a high-resolution CAT scan will frequently demonstrate abnormalities. Lung function testing is distinctly abnormal.

The diagnosis can be confirmed by lung biopsy. An open surgical biopsy, meaning that the chest wall must be surgically opened under general anesthesia to remove a portion of lung tissue, may be necessary to obtain enough tissue to make an accurate diagnosis. The removed tissue is examined microscopically by a pathologist to confirm the presence of fibrosis.

How is the pulmonary fibrosis treated?

The treatment options for idiopathic pulmonary fibrosis are very limited. There is no evidence that any medications can help this condition, because scarring is permanent once it has developed. Lung transplantation is the only therapeutic option available, but this is usually reserved for advanced cases. At times, this diagnosis can be difficult to make even with tissue biopsy reviewed by pathologists with specific experience in this field. Research trials using different drugs that may reduce fibrous scarring are ongoing. Because some types of lung fibrosis can respond to corticosteroids (such as Prednisone) and/or other medications that suppress the body's immune system, these types of drugs are sometimes prescribed in an attempt to decrease the processes that lead to fibrosis. When these fail, lung transplantation may be considered for some patients.