Coordinated Health


Caplan syndrome is swelling (inflammation) and scarring of the lungs in people with rheumatoid arthritis who have been exposed to mining dust containing coal. The lung disease is called coal worker’s pneumoconiosis.

Alternative Names

Rheumatoid pneumoconiosis

Causes, incidence, and risk factors

Caplan syndrome is caused by breathing in coal mining dust. This causes inflammation and can lead to the development of many small lung lumps (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
  • Joint swelling and pain
  • Nodules of the skin (rheumatoid nodules)
  • Shortness of breath
  • Wheezing

Signs and tests

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 any joint and skin disease.

Other tests can include:

  • Chest x-ray
  • CT scan of the chest
  • Joint x-rays
  • Pulmonary function tests
  • Rheumatoid factor test


There is no specific treatment for Caplan syndrome, other than treating any lung and joint disease.

Support Groups

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.

Expectations (prognosis)

Caplan syndrome rarely causes serious breathing trouble or disability due to lung problems.


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

Calling your health care provider

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.