20th February 2025

Pneumoconiosis

Overview of pneumoconiosis

Pneumoconiosis, or occupational interstitial lung disease, refers to lung inflammation and fibrosis which occurs due to inhalation of mineral and metal dusts, often in the work environment. Due to the occupational nature of many of these diseases, financial compensation may be available for those affected.

Amongst the major types of pneumoconiosis are asbestosis, coal worker’s pneumoconiosis and silicosis.

Asbestosis

Overview and diagnosis of asbestosis

Asbestosis is interstitial fibrosis secondary to asbestos inhalation. Disease severity is correlated with length of exposure, type and quantity of asbestos.

Symptoms include gradual-onset shortness of breath and dry cough. Examination may reveal bi-basal inspiratory crackles and clubbing.

Diagnosis involves:

• Imaging: asbestosis can resemble IPF on CXR and HRCT, with reticulonodular shadowing (CXR) and subpleural fibrosis (CT). The presence of pleural thickening and plaques help to make the diagnosis of asbestosis
• Lung function tests: typically a restrictive pattern
• Biopsy: asbestos bodies may be seen

Management of asbestosis

There is no effective drug treatment for asbestosis. Supportive treatment including home oxygen may be required in advanced stages. Lung transplant is rare but can be considered.

As a high proportion of those with asbestosis die from malignancy, and cigarette smoking increases the severity and rate of progression of asbestosis, it may be appropriate to advise patients to stop smoking.

See note on nintedanib – this has now been approved as a treatment option for chronic progressive fibrosing interstitial lung diseases.

Coal worker’s pneumoconiosis

Overview and diagnosis of coal worker’s pneumoconiosis

This is an ILD caused by the inhalation and deposition of coal dust in the lung. Macrophages engulf coal dust particles and form coal macules. These accumulate throughout the lung and ultimately lead to focal emphysema.

This condition may be asymptomatic and respiratory examination is often normal.

Symptoms, if present, include gradual-onset shortness of breath (particularly on exertion), cough and wheeze. Patients may produce black-pigmented sputum.

History is an essential part of diagnosis to determine exposure.

Investigations include:

• CXR and HRCT: nodules, predominantly in the upper and middle zones, and there may be distortion of lung architecture and emphysema
• Lung function tests: a mixed obstructive and restrictive picture in severe disease

Management of coal worker’s pneumoconiosis

Management is mostly supportive. Avoidance of exposure or using personal protective equipment is of benefit. If there is evidence of COPD as a complication, bronchodilator therapy might be tried.

See note on nintedanib – this has now been approved as a treatment option for chronic progressive fibrosing interstitial lung diseases.

Caplan syndrome

Caplan syndrome describes lung fibrosis in the context of a history of exposure to coal dust on a background of rheumatoid arthritis. Symptoms include cough and shortness of breath as well as painful joints and morning stiffness. Signs include features of RA.

Treatment involves cessation of dust exposure and smoking. Steroids can be used after TB is excluded and DMARDs should be considered for the treatment of RA.

Silicosis

Overview and diagnosis of silicosis

Resulting from inhalation of silica particles, often used in industries such as stone masonry and ceramics, silicosis is a heavily fibrosing pneumoconiosis which often develops many years after exposure. There are various subtypes with different chronicities.

Symptoms include dry cough and shortness of breath.

There is an increased incidence of active TB in people with silicosis; this is described as silicotuberculosis. Symptoms such as haemoptysis or fever should prompt further investigation for TB.

Management of silicosis

There is no effective pharmacological treatment for silicosis. Smoking cessation should be advised due to increased risk of lung cancer, as silica itself is carcinogenic. Bronchodilators can help if there is an element of obstruction.

In severe cases, lung transplant can be considered.

See note on nintedanib – this has now been approved as a treatment option for chronic progressive fibrosing interstitial lung diseases.

References

• Cullinan P, Reid P. Pneumoconiosis. Prim Care Respir J. 2013;22(2):249-52
• DeLight N, Sachs H. Pneumoconiosis. StatPearls. Treasure Island (FL)2021
• Chapman SJR, G. V.; Shrimanker, R. S.; Turnbull, C. D.; Wrightson, J. M. Oxford Handbook of Respiratory Medicine. Fourth Edition ed. Oxford, United Kingdom: Oxford University Press; 2021
• Rosenman K. Pneumoconioses: BMJ best practice; 2020. Available from: https://bestpractice.bmj.com/topics/en-gb/1112 [accessed 05/01/2022]
• Caplan A. Rheumatoid disease and pneumoconiosis (Caplan’s syndrome). Proc R Soc Med. 1959;52:1111-3
• Draper R. Caplan’s Syndrome: Patient; 2011. Available from:  https://patient.info/doctor/Caplan’s-Syndrome.htm [accessed 05/01/2022]
• NICE. Nintedanib for treating progressive fibrosing interstitial lung diseases. National Institute for Health and Care Excellence, 2021 [accessed 18/03/2024]