What are the other Names for this Condition? (Also known as/Synonyms)

• Caplan Disease
• Rheumatoid Pneumoconiosis

What is Caplan Syndrome? (Definition/Background Information)

• Caplan Syndrome is inflammation (swelling) and scarring of the lung tissue. It occurs in individuals that have rheumatoid arthritis as well as coal worker’s pneumoconiosis
  • Rheumatoid arthritis is the most common type of autoimmune arthritis, in which the body’s own defense system attacks the small joints of the hands and feet
  • Coal worker’s pneumoconiosis (CWP), or black lung disease, is an occupation-based lung disease caused by the inhalation of coal dust. Individuals over the age of 50, who work in coal and graphite mines and coal storage facilities, are primarily at risk for being diagnosed with the condition
• There is not enough evidence to depict age and sex distribution for Caplan Syndrome. It manifests as intrapulmonary nodules (occurring within the lung), which are well-defined, when seen on a chest X-ray
• Caplan Syndrome presents with cough and shortness of breath. It is generally treated with steroids, following the exclusion of tuberculosis. The prognosis of the condition depends directly on the severity of the rheumatoid arthritis and lung damage caused by coal exposure

Who gets Caplan Syndrome? (Age and Sex Distribution)

• Currently, Caplan Syndrome is known to affect 1 in 100,000 individuals. However, this ratio is declining as old industrial practices of the coal mining industry is in decline (also, many coal mines have shut down)
• Rheumatoid arthritis is 3-5 times more common in women than men. However, coal worker’s pneumoconiosis mainly affects men as they predominantly work in mines
• There is no current research specifically representing the age and sex distribution for Caplan Syndrome
• Caplan Syndrome may be more common in some parts of the world, but it is extremely rare in the United States

What are the Risk Factors for Caplan Syndrome? (Predisposing Factors)

The risk factors for Caplan Syndrome include:

• Coal mining: Inhalation of the dust from working in coal mining industry is the single largest risk factor for the condition
• Genetic predisposition: Some individuals are at an increased risk for developing the disease because of their genetic makeup
• Smoking: Although it is not a known cause, it can contribute to the severity of the syndrome

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Caplan Syndrome? (Etiology)

Black lung disease (coal worker’s pneumoconiosis) with large rheumatoid lung nodules is called Caplan Syndrome. It is a rare manifestation in black lung disease with rheumatoid arthritis.

• Inhaling mining dust (coal, asbestos, silica) leading to inflammation of the lung causes Caplan syndrome
• The inflammation may cause many small lumps in the lungs and result in the development of an airway disease similar to mild asthma
• Some individuals that have been exposed to coal dust for prolonged periods present with severe lung scarring, making it difficult for the lungs to carry oxygen to their bloodstream (known as progressive massive fibrosis)

Some researchers support genetic predisposition as a potential cause for Caplan Syndrome.

What are the Signs and Symptoms of Caplan Syndrome?

The signs and symptoms of Caplan Syndrome may include:

• Cough
• Joint inflammation and associated pain
• Shortness of breath
• Wheezing
• Rheumatoid nodules (lumps under the skin)
  • They occur bilaterally and peripherally varying from 0.5 cm to 5.0 cm in size
  • The nodule can remain the same size, grow, resolve or disappear, and then reappear 
• Chest examination may present diffuse rales (abnormal rattling sound heard when listening to an unhealthy lung) that remains when the individual coughs or takes a deep breath

How is Caplan Syndrome Diagnosed?

Caplan Syndrome may be diagnosed by via the following tests and exams:

• Complete physical examination, medical history (including occupational history) evaluation, and assessment of the presenting signs and symptoms
• Lung function test may expose restrictive or obstructive defects with loss of lung volume
• Rheumatoid factor test and other blood tests (antinuclear antibodies and non-organ specific antibodies)
• Joint X-rays and joint fluid analysis, if needed
• Chest radiology imaging studies may show nodules, which may resemble tuberculosis

Differential diagnosis: Silicosis and asbestosis must also be considered (excluded) when diagnosing an individual with Caplan Syndrome.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Caplan Syndrome?

The complications of Caplan Syndrome may include:

• Severe breathing difficulties
• Lung scarring (progressive massive fibrosis)
• Increased risk for tuberculosis
• Reduced quality of life

How is Caplan Syndrome Treated?

There is no specific treatment for Caplan Syndrome except for treating the lung or joint disease symptoms that are present.

• Steroids are used once tuberculosis is excluded
• Rheumatoid arthritis is treated using disease-modifying antirheumatic drugs (DMARDS)
• Oxygen supplementation may be necessary in some cases
• The use of inhalers/bronchodilators may be recommended
• Smokers are advised to stop smoking immediately to prevent progression of the syndrome
• Physical therapy

Regular medical screening at periodic intervals with tests and physical examinations are necessary and recommended.

How can Caplan Syndrome be Prevented?

• Individuals with rheumatoid arthritis should avoid working in coal mines to prevent exposure to coal dust
• Adequate preventative gear should be worn including face masks to prevent coal dust particulate inhalation
• Proper industry safety standards should be put in place to ensure safety of the workers exposed to coal dust

What is the Prognosis of Caplan Syndrome? (Outcomes/Resolutions)

• The prognosis for Caplan Syndrome is generally similar to that of rheumatoid arthritis. Even though rheumatoid arthritis is not a fatal condition, complications that arise from Caplan Syndrome may shorten survival by a few years
• Although the life span is not adversely affected in rheumatoid arthritis, individuals with rheumatoid arthritis are at an increased risk of developing lung disease, heart problems, infections, stomach problems, and cancer

Additional and Relevant Useful Information for Caplan Syndrome:

Caplan Syndrome is a combination of rheumatoid arthritis and pneumoconiosis. For additional information please refer to the following links:

https://www.dovemed.com/diseases-conditions/rheumatoid-arthritis-ra/

https://www.dovemed.com/diseases-conditions/black-lung-disease/