Idiopathic pulmonary fibrosis

Definition

Idiopathic pulmonary fibrosis is scarring or thickening of the lungs without a known cause.

Alternative Names

Idiopathic diffuse interstitial pulmonary fibrosis; IPF; Pulmonary fibrosis; Cryptogenic fibrosing alveolitis; CFA; Fibrosing alveolitis; Usual interstitial pneumonitis; UIP

Causes, incidence, and risk factors

No one knows what causes idiopathic pulmonary fibrosis or why some people get it. It causes the lungs to become scarred and stiffened. This stiffening may make it increasingly difficult to breathe. In some people the disease gets worse quickly (over months to a few years), but other people have little worsening of the disease over time.

The condition is believed to be due to an inflammatory response to an unknown substance or injury. "Idiopathic" means no cause can be found. The disease occurs most often in people between 50 and 70 years old.

Symptoms

• Chest pain (occasionally)
• Cough (usually dry)
• Decreased tolerance for activity
• Shortness of breath during activity (this symptom lasts for months or years, and over time may also occur when at rest)

Signs and tests

The health care provider will perform a physical exam and ask questions about your medical history. Your doctor will ask whether you have been exposed to asbestos and if you have been a smoker.

Patients with idiopathic pulmonary fibrosis have abnormal breath sounds called crackles. Patients with advanced disease may have blue-colored skin (cyanosis) around the mouth or in the fingernails due to low oxygen.

Examination of the fingers and toes may show abnormal enlargement of the fingernail bases (clubbing).

Tests that help diagnose idiopathic pulmonary fibrosis include the following:

• Bronchoscopy with transbronchial lung biopsy
• Chest CT scan
• Chest x-ray
• Measurements of blood oxygen level
• Pulmonary function tests
• Six-minute walk test
• Surgical lung biopsy
• Tests for connective tissue diseases such as rheumatoid arthritis, lupus, or scleroderma

Treatment

No known cure exists for idiopathic pulmonary fibrosis. Unfortunately, no medication has been shown to improve the outcome of patients with this condition.

• For some people, medications such as corticosteroids and cytotoxic drugs may help reduce swelling (inflammation). However, these drugs might also increase the risk of death.
• Other new treatments that have been shown to help some people with idiopathic pulmonary fibrosis are being studied.
• Patients with low blood oxygen levels may need oxygen.
• Lung rehabilitation will not cure the disease, but it can help maintain exercise capacity (the ability to exercise without breathing difficulty).

You can make home and lifestyle changes to manage breathing symptoms. Anyone who smokes should stop right away.

Some patients with advanced pulmonary fibrosis may need a lung transplant.

Support Groups

You can ease the stress of illness by joining a support group where members share common experiences and problems.

The following organizations are good resources for information on lung disease:

• American Lung Association - www.lungusa.org
• National Heart, Lung, and Blood Institute - www.nhlbi.nih.gov

Expectations (prognosis)

Some patients may improve or stay stable for a long time when they are treated with corticosteroids or cytotoxic drugs. However, in most people the disease can get worse even with treatment. This worsening can happen quickly, or very slowly.

When breathing symptoms become more severe, discuss treatments that prolong life, health care agents, and advanced care directives with your health care provider.

Complications

• Abnormally high levels of red blood cells due to low blood oxygen levels
• Collapsed lung
• High blood pressure in the arteries of the lungs
• Respiratory failure

Calling your health care provider

Call your health care provider if your breathing is:

• Getting harder
• Faster than before
• Shallow, and you cannot get a deep breath

Also call your health care provider if:

• You need to lean forward when sitting to breathe comfortably.
• You are using muscles around your ribs to help you breathe.
• You are having headaches more often.
• You feel sleepy or confused.
• You have a fever.
• You are coughing up dark mucus.
• Your fingertips, or the skin around your fingernails is blue.

Prevention

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References

American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and Latin American Thoracic Association (ALAT). Idiopathic pulmonary fibrosis: evidence based guideline for diagnosis and management. Am J Respir Crit Care Med. 2011; 183:788-824.

Selman M, Morrison LD, Noble PW, King TE Jr. Idiopathic interstitial pneumonias. In: Mason RJ, Broaddus VC, Martin TR, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 57.