RP is caused by breathing in inorganic dust. This is dust that comes from grinding metals, minerals, or rock. After the dust enters the lungs, it causes inflammation. This can lead to the formation of many small lumps in the lungs and an airway disease similar to mild asthma.

It is not clear how RP develops. There are two theories:

• When people breathe in inorganic dust, it affects their immune system and leads to rheumatoid arthritis (RA). RA is an autoimmune disease in which the body's immune system attacks healthy body tissue by mistake.
• When people who already have RA or are at high risk for it are exposed to mineral dust, they develop RP.

Symptoms of RP are:

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

Your health care provider will take a detailed medical history. It will include questions about your jobs (past and present) and other possible sources of exposure to inorganic dust. Your 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
• Lung function tests
• Rheumatoid factor test and other blood tests

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

Stop exposure to coal dust.

Attending a support group with people who have the same disease or a similar disease can help you understand your condition better. It can also help you adjust to your treatment and lifestyle changes. Support groups take place online and in person. Ask your provider about a support group that might help you.

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

These complications can occur from RP:

• Increased risk for tuberculosis
• Scarring in the lungs (progressive massive fibrosis)
• Side effects from medicines you take

Contact your provider for an appointment if you have symptoms of RP and exposure to coal dust.

Talk to your provider about getting the flu and pneumonia vaccines.

If you've been diagnosed with RP, contact your provider right away if you develop a cough, shortness of breath, fever, or other signs of a lung infection, especially if you think you have the flu. Since your lungs are already damaged, it's very important to have the infection treated promptly. This will prevent breathing problems from becoming severe, as well as further damage to your lungs.

People with RA should avoid exposure to inorganic dust.

RP; Caplan syndrome; Pneumoconiosis - rheumatoid; Silicosis - rheumatoid pneumoconiosis; Coal worker's pneumoconiosis - rheumatoid pneumoconiosis

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Go LHT, Cohen RA. Pneumoconioses. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 101.

Raghu G, Martinez FJ. Interstitial lung disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 86.

Tarlo SM. Occupational lung disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 87.

Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.