Silicosis

Definition

Silicosis is a respiratory disease caused by breathing in (inhaling) silica dust.

Causes

Silica is a common, naturally-occurring crystal. It is found in most rock beds and forms dust during mining, quarrying, tunneling, and working with many metal ores. Silica is a main part of sand, so glass workers and sand-blasters are also exposed to silica.

Three types of silicosis ocur:

Progressive massive fibrosis can occur in either simple or accelerated silicosis, but is more common in the accelerated form. Progressive massive fibrosis causes severe lung scarring and destroys normal lung structures.

People who work in jobs where they are exposed to silica dust are at risk. These jobs include:

Intense exposure to silica can cause disease within a year, but it usually takes at least 10 - 15 years of exposure before symptoms occur. Silicosis has become less common since the Occupational Safety and Health Administration (OSHA) created regulations requiring the use of protective equipment, which limits the amount of silica dust workers inhale.

Symptoms

Exams and Tests

Your health care provider will take a medical history that includes many questions about your jobs (past and present), hobbies, and other activities that may have exposed you to silica. The health care provider will also do a physical exam.

Tests to confirm the diagnosis and rule out similar diseases include:

Treatment

There is no specific treatment for silicosis. Removing the source of silica exposure is important to prevent the disease from getting worse. Supportive treatment includes cough medicine, bronchodilators, and oxygen if needed. Antibiotics are prescribed for respiratory infections as needed.

Treatment also includes limiting exposure to irritants, quitting smoking, and having routine tuberculosis skin tests.

People with silicosis are at high risk for developing tuberculosis (TB). Silica is believed to interfere with the body's immune response to the bacteria that cause TB. People with silicosis should have skin tests to check for exposure to TB. Those with a positive skin test should be treated with anti-TB drugs. Any change in the appearance of the chest x-ray may be a sign of TB.

Patients with severe silicosis may need to have a lung transplant.

Support Groups

Joining a support group where you can meet other people with silicosis or related diseases can help you understand your disease and adapt to its treatments.

Outlook (Prognosis)

The outcome varies depending on the amount of damage to the lungs.

Possible Complications

When to Contact a Medical Professional

Call your health care provider if you are exposed to silica at work and you have symptoms of the disease.

Prevention

If you work in a high-risk occupation or have a high-risk hobby, wear dust masks and do not smoke. You might also want to use other protection recommended by OSHA, such as a respirator.


Review Date: 6/10/2011
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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