Caplan syndrome is swelling (inflammation) and scarring of the lungs in people with rheumatoid arthritis who have been exposed to mining dust, such as coal, silica, or asbestos.

Caplan syndrome is caused by breathing in mining dust, which causes inflammation and can lead to the development of many small lung bumps (nodules) and mild asthma-like airway disease.

Some people who have been exposed to the dust have severe lung scarring that makes it difficult for their lungs to carry oxygen to the bloodstream (called progressive massive fibrosis). People with rheumatoid arthritis do not seem more likely to have this complication of scarring. Caplan syndrome is very rare in the United States.

• Cough
• Shortness of breath
• Wheezing
• Nodules of the skin (rheumatoid nodules)
• Joint swelling and pain

Your health care provider will take a detailed medical history that will include questions about your jobs (past and present) and other possible sources of exposure to mining dust. The health care provider will also do a physical exam, paying special attention to the presence of joint and skin disease.

Other tests can include:

• Chest x-ray
• Joint x-rays
• Pulmonary function tests
• Rheumatoid factor titer test

There is no specific treatment for Caplan syndrome.

Attending support groups with other people who have similar diseases can help you understand your disease and adjust to its treatment and other lifestyle changes.

Caplan syndrome rarely causes serious breathing trouble or disability, but it can increase the risk for tuberculosis (TB). People who have it should be screened for exposure to TB.

• Side effects of medications
• Increased risk for tuberculosis
• Progressive massive fibrosis (scarring)

Call for an appointment with your health care provider if you have symptoms of Caplan syndrome.

People with rheumatoid arthritis should avoid exposure to hazardous dust.

Murray J, Nadel J. Textbook of Respiratory Medicine. 3rd ed. Philadelphia, Pa: WB Saunders; 2000:1619-1721.